Melinda Gates

Maybe it should be called the Melinda & Bill Gates Foundation. Her influence over the world's largest foundation is enormous -- Bill has said it wouldn't exist if it weren't for her. She has championed not only big-picture, tech-oriented solutions to improve health and education over the long term but also more modest steps to help the poorest of the poor right now, such as distributing condoms. The foundation's latest surprise: funding health and education messages to be integrated into Viacom TV programming. Sneaky? Perhaps. Daring? For sure -- and that's what Gates, 44, expects of the foundation. "We will get out there and try something," she told Vogue this year. "If it doesn't work, we will try something else. And we will keep trying until we find something that works." -- by Jeff Chu