Carly Fiorina declared her candidacy for the U.S. Senate–in a bid to replace another well-known woman, incumbent California Democrat Barbara Boxer.

Fiorina, who was No. 1 on Fortune’s Most Powerful Women list for six years when she was CEO of Hewlett-Packard (HPQ), will be pounding the campaign trail simultaneously with another ex-No. 1 on our list: Meg Whitman. The former eBay (EBAY) CEO, who topped Fortune’s power list in 2004 and ‘05, is running for Governor.

Neither woman, both Republicans, will have an easy time in the left-leaning, financially crippled Golden State. Running on her “I’m a great manager” platform, Whitman has a decent shot at her party’s nomination. But she faces a fierce Democratic rival in Jerry Brown, California’s current Attorney General who once was Governor. Another Democratic rival, San Francisco Mayor Gavin Newsom, just dropped out. (For more, check out my recent cover story, “Can Meg Whitman Save California?“)

Fiorina, who yesterday revealed her plans in the Orange County Register, has a personality tailor-made for campaigning: She’s charismatic and commanding. Remember when she was waging that brutal proxy fight to buy Compaq in 2002? She played it like a political candidate–and she won.

But Fiorina, 55, who worked with Whitman on John McCain’s failed Presidential campaign, carries significant baggage into this latest race: She was fired by the H-P board in 2005–as much for her style of leadership as her disappointing execution.

Another battle lately has been a medical one. Fiorina was recently treated for breast cancer. In September, while undergoing daily treatments at Stanford Hospital, she spoke by video-conference, along with Elizabeth Edwards, to participants of the Fortune Most Powerful Women Summit. Here’s a clip:

Kudos to Fiorina for speaking out. The fact that she’s running for the U.S. Senate is a sign that her prognosis is good. And she’s as tenacious as ever.

“We don’t get a chance to do that many things, and every one should be really excellent. Because this is our life. Life is brief, and then you die, you know? So this is what we’ve chosen to do with our life. We could be sitting in a monastery somewhere in Japan. We could be out sailing. Some of the [executive team] could be playing golf. They could be running other companies. And we’ve all chosen to do this with our lives. So it better be damn good. It better be worth it. And we think it is.”

– Apple (AAPL) CEO Steve Jobs said this to Fortune’s Betsy Morris last year but his words resonate now more than ever. Today, Apple reported its most profitable quarter in history, earning $1.82 a share on revenue of $9.87 billion for the fourth fiscal quarter of 2009. The results far exceeded expectations and sent shares soaring, up from the closing price of $189.86 to $202.87 by 5:41 p.m. — an all-time high. “We are thrilled to have sold more Macs and iPhones than in any previous quarter,” Jobs said in a prepared statement. While the monastery, sailing and golf are all interesting options, can there be any doubt that Jobs made the right choice? –Jessica Shambora

From the sublime–yesterday’s post about extraordinary women spreading their power throughout the developing world–to the ridiculous.

Perhaps ridiculous, but important nonetheless…

This afternoon, I walked over to Bloomberg headquarters at 58th and Lex to hear an author, a former Goldman Sachs (GS) managing director named Sharon Meers, talk about high-achieving men and women and how to stay successful and sane and married all at the same time.

Meers co-wrote a book called Getting to 50/50, which was released a few months ago. Lots of fascinating stats, but some of the most intriguing revolved around the male-female balance of work at home. In today’s talk to about 200 Bloombergers (a gender-balanced crowd), Meers mentioned  that when couples share housework, the risk of divorce drops.

Divorce risk drops sharply when the wife has a job. The ideal set-up is when the man earns 60% of the income and does 40% of the housework. That’s when divorce risk is lowest of all.

(The sex is also better then, by the way. When men do substantial housework, couples have more frequent and satisfying sex. Meers shared this factoid privately, and she lays it all out in her book, in a section called “When He Does Windows…”)

And where in the world do men do the most to help their wives at home? Meers doesn’t have those stats, but I found them, coincidentally, yesterday in a preview of another book due out in September. Women Want More, by Boston Consulting Group senior partner Michael Silverstein, is a marketer’s guide to capturing “the world’s largest and fastest-growing market.” As part of the research for the book, BCG asked 12,000 women in 22 countries a battery of 120 questions. And among the rich findings…

“At least one-third of men never help their wives/partners with chores,” according to the BCG survey. Where do men do the least housework? Japan. Indian men do the most. And American men? They come somewhere in between, though closer to India than Japan.

By the way, chores cause more domestic arguments than anything else except money–at least in the U.S., the BCG survey suggests. In Europe, BCG found, chores are the No. 1 trigger of domestic arguments.

That doesn’t surprise author Meers. “Among people over 40,” she says, “two-thirds of divorces are initiated by women. And studies show that 80% of the fights are about housework.”

Carol Bartz can handle pain.

In January, she walked into the CEO job at Yahoo (YHOO), unfazed by the company’s demoralized workforce, fractured management, and angry investors.

Seven month later, she’s taking flak for Yahoo’s new search partnership with Microsoft (MSFT).

And did you hear that when she announced that deal–to secure a fighting chance in the lucrative search business against mighty Google (GOOG)–Bartz was recovering from knee-replacement surgery?

Well, you don’t know the half of it.

Bartz had the surgery with local anesthesia–an epidural to numb her lower body.

She watched the entire operation.

And she savored every gory minute of it.

Do normal people do this? “Normal people don’t do it,” Bartz admitted yesterday as she offered color commentary on the 47 minutes of cutting, hammering, and retrofitting an artificial left knee where her 60-year-old real one used to be.

Bartz, bear in mind, has never been normal when it comes to her own health issues. At 43, when she joined Autodesk (ADSK) as CEO, she was diagnosed with breast cancer that very week. She worked through months of chemotherapy, taking off one month to have surgery.

“I watched them saw my leg in half,” Bartz said about this latest medical adventure, enthusiastically detailing the skin, fat, cartilage and bone that she viewed on a video monitor perched beside her head on the operating table. “I asked, ‘Where’s the blood?’” To her surprise, there was hardly any. Thanks goes to a hefty tourniquet that her surgeon, Dr. John Dearborn at Washington Hospital in Fremont, California, used to keep the operation not too messy.

Bartz is spending this week in Hawaii, on vacation and recovering from the July 8 surgery, as well as from the eviscerating reaction to the Microsoft partnership, which was announced July 29. (Yahoo stock has dropped from $17 to below $15 since then.)

“You have to go back to the center–why it was important,” she says about the deal and Wall Street’s displeasure. “It’s important for the long-term health of Yahoo. It’s important to grow audience.” Essentially, she’s slicing off a piece of Yahoo, search technology and engineering, and giving it to Microsoft so that Yahoo can focus on selling on-line advertising and developing on-line content.

As for her own surgical procedure, Bartz says that Dr. Dearborn did six other knees the same day he did hers. She was his only patient, she boasts, who went straight from bed to walking with a cane–no walker. “And I was off the cane in a day and a half,” she adds.

The pain is not getting better each day. “It swells up like a balloon,” Yahoo’s boss says about her new joint. That’s when it really hurts. But she’s bearing it. Now, she notes, she has one fake left knee and one fake “left boob. That’s the bionic side of me.”

Bartz, by the way, did not grant an interview, per se, to talk about her surgical ordeal. I was speaking with her about this year’s Fortune Most Powerful Women issue (which will be out in mid-September) and simply asked how she was feeling. The conversation proceeded. At the end when I asked if I could share details of her surgery, Bartz said, “Sure, as long as you pass on two pieces of advice.”

“Stop jogging,” she said. “And stop playing singles tennis.”

Yahoo’s never-say-die chief executive pushed herself too far for too long, with bad body parts. Once she recovers from this, will she go back to running or tennis? “No, I’m down to one sport,” Bartz says. “Golf.”

“If you spend your whole life focused on getting from here to there, then you won’t enjoy the trip.”

- Sallie Krawcheck, suggesting that her move to Bank of America (BAC), announced today, isn’t about chasing the golden rung–the CEO job there–but rather about fulfilling a desire “to get back in the fray.”  I’ve known Krawcheck, who had an unpleasant parting with Citigroup (C) last fall, for many years. And though I don’t doubt her ambition to rise to the top level, I think she’s more motivated to be a role model for her industry–in her case, managing investors’ wealth–than to be a big-bank boss, which isn’t very fun these days anyway. Who would want to be BofA CEO Ken Lewis, after all? The candidates are nevertheless lining up. For more on who they are and on Krawcheck’s reemergence, read “Behind Sallie Krawcheck’s move to BofA.”

Gerri Elliott, one of Microsoft’s (MSFT) star execs, left the company early this year to spend more time with her family. Yes, seriously to spend time with her family. As I wrote in January, her departure was a major loss for Microsoft, according to senior executives there, and it was also a case of a powerful woman asking, “Why kill myself and miss my kids growing up?”

Now Elliott, who spent 22 years at IBM (IBM) before moving to Microsoft and heading the $8 billion Worldwide Public Sector unit there, has finished her hands-on familial gig and hasn’t taken long to find a new one back in the business world. Today, Juniper Networks (JNPR) announced that Elliott is coming on board in a new position crafted for her: EVP of Strategic Alliances.

Elliotts’s friends and former colleagues aren’t surprised. She and Juniper’s CEO, Kevin Johnson, have known each other for two decades, going back to their stints together at IBM and Microsoft. In fact, Elliott says she remembers the day 17 years ago when Johnson walked into her IBM office and told her he was leaving to go to upstart Microsoft. He asked her if she would take him back if he screwed up. Little did Johnson know — or Elliott either — that he would rise to head Microsoft’s biggest business, Windows, and one of its toughest, search.

For a decade, Johnson tried to hire Elliott at Microsoft. But she was a bleed-Blue loyalist. Caving in 2001, she flew from Connecticut to Seattle on September 10. Her first day at Microsoft was 9/11. Between running the company’s enterprise business in the Americas, co-heading the Americas organization, and leading the global Public Sector, Elliott handled some of Microsoft’s largest customers–which include countries and government agencies.

After she left in January, she followed the advice of a good friend: She didn’t take headhunter calls for two months. “I wanted and needed this break with my daughter,” Elliott, 53, told me in an email today. But the phone didn’t stop ringing, and eventually she considered CEO positions at start-ups, a president post at a Fortune 500 company,and COO and EVP jobs at several tech companies.

The only thing that really excited her was working with Johnson again. “He’s an exec who cares about the whole person,” she says — and he proved his worth by agreeing to put in Elliott’s Juniper employment contract that she’ll be able to go to the Fortune Most Powerful Women Summit. That’s the annual confab that I chair, and yes, I was shocked when Elliott told me that this event is so important to miss.)

Also in Elliott’s new contract: permission to participate in the annual Fortune – U.S. State Department Global Women Leaders Mentoring Partnership. This is a program that brings rising-star women from developing countries to shadow American women who participate in the MPWomen Summit. Since we launched the program in 2006, Elliott has been one of the program’s most supportive mentors.

So Johnson has lured Elliott to Silicon Valley by tailoring the job to her. The other clincher, she says: Juniper values partnerships. “I mean really values them, like it’s in their DNA,” she says. Elliott will hit the ground running and work to fortify the networking giant’s existing partnership with Nokia (NOK), Siemens (SI) and IBM.  Actually, she’s hard at work already. When I checked in with her earlier today, she was on the road with Johnson, visiting a Fortune 500 giant and trying to strike another major alliance. — Pattie Sellers

The ouster of Bank of America’s (BAC) chief risk officer, Amy Brinkley, was inevitable, as I wrote in “Behind the shakeup at BofA” on Friday.

And as I mentioned in that piece, two years ago, Fortune featured Brinkley and five other execs in “One Step Away,” about rising-star Most Powerful Women on track to be CEOs of Fortune 500 companies someday. So what’s happened to the other five?

One woman made it to the top: Ellen Kullman became CEO of DuPont in January.

Avon (AVP) President Liz Smith is on track to succeed Andrea Jung as CEO there.

Schering-Plough pharma boss Carrie Cox will soon be working for Merck (MRK), pending its  $41 billion acquisition likely to close in the fourth quarter.

And the other two women in “One Step Away”? They’re off the career ladder, like Brinkley. Morgan Stanley (MS) co-president Zoe Cruz has been on the sidelines since John Mack booted her in late 2007. As at BofA, her dismissal was a case of a CEO taking out a top deputy over serious risk-management problems.

Meanwhile, Susan Arnold’s opt out was voluntary. When the Procter & Gamble (PG) President quit her post last March, one day after her 55th birthday, she did it to take back her life. As for returning to a big corporate job, who knows? She’s not deciding yet, she told me. Meanwhile, she’s staying in the game by serving on the boards of Walt Disney and McDonald’s.

Here’s the reality: In this stressful environment, more and more top business women are questioning the worth of their careers. Last month came a retirement announcement from one of Wal-Mart’s (WMT) most senior women, Linda Dillman, at the top of her game. Dillman, EVP of Benefits and Risk Management at Wal-Mart, never lusted for big titles. I bet she’ll return to her roots: information technology.

Another veteran of Fortune’s Power 50 list, Sue Hellmann, recently quit her job as president of product develepment at Genentech to become Chancellor of the University of California, San Francisco.

More and more women are making big life choices. Because real power is being able to choose. That’s a point that Claire Shipman and Katty Kay write about extensively in their new book, Womenomics.

By the way, I hear that Amy Brinkley is doing okay. She certainly isn’t proud of failing to keep BofA well-capitalized and sturdy. But she’s part of a sweeping reorg there, and more change will come as CEO Ken Lewis fights to keep control. It may be small comfort, but there’s less shame in losing your job now than there has been in our lifetimes.

“Every time you celebrate an achievement, be thankful to those who made it possible.”

–Steven Chu, U.S. Secretary of Energy, in his address to Harvard grads Thursday. Chu encouraged students to give a shout out to parents, friends and inspirational professors. “Especially thank the other professors whose less-than-brilliant lectures forced you to teach yourself. Going forward, the ability to teach yourself is the hallmark of a great liberal arts education and will be the key to your success.”

Chu compared the structure of his speech to a “classical sonata.” The final movement was a plea for the new crop of Crimson alum to take on the threat of climate change. “As our future intellectual leaders, take the time to learn more about what’s at stake, and then act on that knowledge. As future scientists and engineers, I ask you to give us better technology solutions. As future economists and political scientists, I ask you to create better policy options. As future business leaders, I ask that you make sustainability an integral part of your business.” Music to our ears. –Jessica Shambora

I’ve been studying women and power since the mid-’90s. And as I’ve learned, women leaders think about power very differently from the way men do.

Power, to most women leaders, is horizontal — about influence across many areas. The careers of successful women tend to be less vertical than a ladder — more like jungle gyms. Many women I know who have reached the top — the top 50 in business, according to Fortune’s annual Most Powerful Women list — have moved laterally, even moving down a notch, to broaden their experience. Peripheral vision is key. Smart women swing to opportunities, over here or over there — maybe after time out to raise kids and build a full life along the way.

A new book called Womenomics captures a lot of my thinking. I have nothing to do with the book, though I know Claire Shipman and Katty Kay, the co-authors. In fact, they’ll be speaking about their research and insights at the Fortune Most Powerful Women Summit this September.

Yesterday Jessica Shambora, my Postcards colleague, and I subwayed downtown to hear Shipman, who is senior national correspondent for ABC’s (DIS) Good Morning America , and Kay, the Washington correspondent and anchor for BBC World News America. They talked about why companies should work to keep women leaders: mainly, because businesses with lots of women at the top perform better. Several studies prove that.

The best stuff that Shipman and Kay shared was about how successful women behave and how smart managers respond. A few nuggets from their talk:

Time is the currency for women. “We’re prepared to trade income and status for time,” says Kay, a mother of four. Both she and Shipman, who has two children, have made that trade in their own careers, passing up promotions — even though women (and men even more) fear the public perception from ratcheting back their ambition. Sara Lee (SLE) CEO Brenda Barnes, who took her own multi-year timeout from a big job after scaling the ranks at PepsiCo (PEP), told the authors that now is a prime time to ask to work less, if you so desire. Why now? Because many bosses are looking to cut costs without laying off people. Notes Kay, “If you look at demographics, there’s a labor and talent shortage looming, so they want to keep you.”

Enlightened companies treat employees like grownups. The real forward-thinking companies encourage employees to get their work done wherever, whenever. “It’s not about face time or office time,” says Shipman. “It’s about what you produce.” She and Kay mentioned Best Buy (BBY), which “abandoned the clock” a few years ago. Giving employees the right to work on their own time and own terms — with clear targets and measurement systems to monitor them — boosted productivity dramatically.

Know yourself. As companies squeeze costs, do more with less, and pile the work — on you! — you need to know what your true value is. “Have the power to say, ‘This is what I can do for you,’” says Kay. She and Shipman lay out ways to appear as if you’re saying Yes when you’re actually saying No to an extreme assignment. Say you can’t possibly finish that report by Friday. You might tell your slave-driving CEO or supervisor: “I’m happy to take this on. I can have it to you by June 27. Do you want me to bring someone else in so we can make an earlier deadline?”

Indeed, in these stressed-out times, when most of us are questioning our jobs and our careers, it’s critical to know what you’re best at and what your priorities are. For more, check out this “Know Yourself” post that I wrote two months ago. And when you have a moment to breathe, check out Womenomics.

“You are certain to change with time and there’s a chance your bliss may evolve too. Not to worry: The skills you acquire can always be effectively redeployed.”

– Tom Freston, the former Viacom (VIAB) whose commencement speech we’ve run in three parts since Wednesday.

As we said, except for Apple’s (AAPL) Steve Jobs’ extraordinary speech to Stanford grads in 2005, Freston’s talk — which he delivered at his son Andrew’s graduation from Emerson in 2007, less than a year after Sumner Redstone fired him — is one of our all-time favorites. The speech hasn’t been circulated until now.

If you haven’t read it this week on Postcards, do check it out. In Part One, Freston sets up his life lessons by talking about his remarkable career. In Part Two, he talks about chasing your bliss and bouncing back from setbacks. Part Three is about getting a grip on the world and being curious — and staying young, no matter your age. The life and career lessons from Freston — who has moved on to work with Oprah and Bono and travel the globe — are timely today, when most of us are asking: “Am I in the right job for me, and what else might I do?”

By the way, what’s your favorite commencement speech? Let us know! — Pattie Sellers