The real power of Fortune Most Powerful Women is the community's reach and influence around the world.

And there's no better testament to this than the Mentor Walks that took place this month in 18 countries, from China to Egypt to Poland to Haiti. These walks, pairing successful career women with younger women and girls, were organized and hosted by alumnae of the Fortune - U.S. State Department Global Women Leaders Mentoring Partnership. This is a program that brings emerging women leaders from developing countries to the U.S. each May to shadow top women execs at companies including IBM (IBM), Johnson & Johnson (JNJ), and Xerox (XRX).

With the help of Vital Voices, Fortune has hosted some 200 rising stars from across the globe since we launched the Mentoring Partnership at our MPW Summit in 2006. The big idea is that these women go home and pay it forward. At her Mentor Walk in Uganda, entrepreneur  Rehmah Kasule gathered more than 1,500 women and girls. Argentina's walk, hosted in Buenos Aires by six alums of the Fortune - State Department Mentoring program, included one of our mentors: Deborah McWhinney, COO of Citi (C) Enterprise Payments. Many MPW mentors pay it forward too.

In this video, three other MPW mentors—Dina Powell of Goldman Sachs (GS), Solera Capital CEO Molly Ashby, and entrepreneur Tory Burch—and another woman who has been a huge supporter of the Fortune - State Department Mentoring program, Secretary of State Hillary Clinton, talk about the value of mentoring women around the world:

By the way, on Tuesday in Silicon Valley, I'll be interviewing another veteran MPW mentor: Yahoo (YHOO) CEO Marissa Mayer. The interview, on stage at Fortune's MPW dinner in Palo Alto, will be Mayer's first time talking to the press since she left Google (GOOG) for the top job at Yahoo last July. Come on back to Postcards and watch the interview with Mayer here on Wednesday.