The smartest people in tech

CEO, Facebook

Some people surely scoffed in 2006 when a 21-year-old college dropout turned down a billion-dollar buyout offer from Yahoo. But from the outset Facebook founder Mark Zuckerberg was sure that the website he started coding from his Harvard University dorm room would be more than a time waster. He was designing a utility -- much like the telephone or the radio before it.

At the company's F8 developers' conference this spring, Zuckerberg, now 26, launched Facebook's most ambitious set of features yet. New social tools let any website (say, Fortune.com) leverage Facebook's network of relationships to make recommendations to visitors who are Facebook users.

Privacy advocates have criticized Zuckerberg for the move, but he's been keenly insightful about what information users want to share on the web. Some analysts say that over time users will start coming directly to Facebook to seek out relevant information, a development that's of concern to one search-engine giant. Outsmarting Google? That's certainly nothing to scoff at. --J.H.

NEXT: Founder runner-up: Marc Benioff