Friendly Faces

Vital Stats: Mark Zuckerberg, 21, of Facebook in Palo Alto, California

Company: Social networking site for college and high school students

Campus Communication: Programming since sixth grade, Zuckerberg caused a sensation while he was a Harvard sophomore. Always looking to ease the transfer of information between groups, he created an online technology that allowed Harvard students to post profiles, browse or search for fellow students, view uploaded pictures, and share their affiliations and interests. Within two weeks, two-thirds of Harvard students signed up. Three weeks after the February 2004 launch, Zuckerberg opened it up to Columbia, Stanford and Yale; now it's available to students (and some alumni) at more than 2,100 colleges and universities internationally and 22,000 U.S. high schools.

Higher Learning: His original intent was not to create a business, but Zuckerberg's success prompted him to take an indefinite leave from Harvard to focus on Facebook. He's still learning plenty: "In the academic world, it was this 'question everything' mentality--never commit to anything that you can't rigorously prove [is] correct," says Zuckerberg. "In the business world, you have to believe in what you're doing and stick to that. That's been an interesting change."

Fulfilling Potential: With more than 7 million users, two-thirds of whom log on daily, Facebook continues to grow with the influx of new users and added features. Says Zuckerberg, "Our vision is to increase information flow and help people express themselves." The soaring popularity of Facebook seems to have piqued the interest of potential buyers--its current valuation is $2 billion. At press time, the company still remained in the hands of Zuckerberg, who has found his entrepreneurial experience "awesome."

"Most people have to work a lot of years to build something cool," he says. "I'm in a different position."