10 BIG THINKERS FOR BIG BUSINESS

Omidyar has made his largest investments so far in the field of microfinance, which empowers the poor around the world by granting tiny loans (often as small as $50) to poor people who want to become entrepreneurs. By helping a woman buy a sewing machine so she can start a clothing business or buy chickens to sell eggs, lenders not only profit from interest payments on the original loans, but also build a base of small-business owners who will continue to bank with them. "It's a perfect match for the way we look at the world," says Omidyar.

Last week the Omidyar Network made a $4 million grant to the nonprofit Grameen Foundation USA, which underwrites more than a million loans in developing countries. Later this year, says one of Omidyar's advisers, the Network will disburse "a significantly larger" amount, intended to be the largest private investment ever in microfinance. In coming years, says Grameen's Alex Counts, "Pierre will become to microcredit what Bill Gates is to global health and vaccines." For a man who changed the world by helping people discover their own entrepreneurial power online, it's a passion that makes perfect sense.

--Karen Breslau

JUDITH REGAN

Judith Regan has never played by the rules. She entered the genteel world of book publishing 18 years ago, a Vassar grad fresh from her gig as a reporter for The National Enquirer, and brought her nose for the sensational and salacious with her. She has offended the tony tastes of her peers ever since, and she's made a fortune doing it. So far this year, four books bearing her ReganBooks imprint have hit No. 1 on The New York Times best-seller list (three related to the Scott Peterson trial, one by former baseball star Jose Canseco). An equal-opportunity provocateur, she has published Rush Limbaugh and Michael Moore, Howard Stern and Eminem, porn star Jenna Jameson and Gen. Tommy Franks. She's responsible for last year's hot erotic memoir "The Surrender" and the "Wizard of Oz"-inspired novel "Wicked." ReganBooks generates a reported $120 million in revenue per year for its parent company, HarperCollins. But Regan's still not sated. "I'm like the rogue warrior of publishing," she says, laughing. A warrior with plans to become the queen of all media? "Well, princess of all media," she says.

In April, Regan announced that she plans to move her company, including about half her 40-person staff, from New York to Los Angeles before the end of the year, and is expanding into television and film. "Who reads?" Regan asks. "The biggest book-buying audience is over the age of 50. I've been screaming to the publishing community about this for years. I mean, hello, this industry is going to have to change!" Raising a son and daughter helped her see the future. "Anyone who has watched children grow up in the last 20 years knows they don't go to bookstores," she says. "Technology is allowing people to get their information in a variety of ways, so why would I limit myself to just books?"