Kristine Pearson stands under a large tree in a remote Rwandan village, patiently showing a circle of wide-eyed teens how to operate large cobalt-blue radios. "Push this button," she tells the children, orphaned like 100,000 of their peers by ethnic cleansing a decade ago (see box) or by disease and now heading households themselves. "Go!" Suddenly two dozen radios explode with the sound of music. Smiles break out all around. "I'm not Mother Teresa," Pearson says later. "But I have this tool, and I can make a difference with it."

In fact, her radios have already improved the lives of hundreds of thousands of impoverished, largely illiterate children across Africa. Charged either by solar power or by a hand crank, the Crayola-bright devices can provide isolated orphans with schooling, news or potentially lifesaving advice on avoiding disease. Since receiving his Lifeline radio last year, "I have learned about AIDS and how I can stop from getting malaria by using mosquito netting," says Jonthan Macumi, 13, who lost his parents and seven of his 10 siblings to what he calls "illness." So valuable are the radios—produced by the Freeplay Energy Group, the technology firm run by Pearson's husband, South African entrepreneur Rory Stear—that children elsewhere in Africa have eagerly traded weapons for them. "I'm in awe of the power and empowerment it represents," says Tom Hanks, one of the high-profile fans of Pearson and the charitable Freeplay Foundation she heads. "The radio can change the world one life, one house, one village at a time."

The foundation has certainly transformed Pearson's life. "I probably would never have been hired for this job I created," admits the fortysomething Californian, who was working in Johannesburg as a bank executive when a mutual friend introduced her to husband-to-be Stear in 1993. Five years later, when he began setting up a foundation—"successful South Africans of my age have an inherent guilt that needs to be worked through," says Stear, now 45—he could not find the right person to run it. Pearson happened to be free, and let herself be talked into spending three months to get the nonprofit off the ground.

Then came Pearson's first trip to distribute radios, to Mozambique in February 1999. "I was immediately hooked," she says. The women and children there told her stories about how the men owned all the radios and would often remove the batteries when they weren't listening so that they wouldn't get used up. "I realized that although there was all this good programming for women and children," she says, "it wasn't reaching them."

That became Pearson's mission. As the foundation's executive director she does everything from courting corporate contributions—in 2002 Vodafone passed Freeplay Energy to rank as the charity's biggest donor—to redesigning the radios. (For a new model introduced last year she created a removable wire antenna, because she'd found that children often broke off the old ones to use for goatherding.) And while some in the international relief community question Pearson's practice of spending foundation funds to purchase the radios from her husband's firm, she has won the support of key philanthropists such as former President Jimmy Carter. "She's what I'd describe as a charming, good-looking bulldozer who simply doesn't take no for an answer," says Sesame Street chairman Vincent Mai. "Which is good, because her intent is incredibly noble."

Ultimately, says Pearson, what matters most to her is the feedback she gets from people like 14-year-old Rwandan orphan Mukakrimba, who received her Lifeline last year. "For a long time the most important thing I had was my goat," the teen said recently. "But now it is my radio."

Pam Lambert. Dietlind Lerner in Rwanda

  • Contributors:
  • Dietlind Lerner.