Mark Zuckerberg
Founder and CEO, Facebook

Since Mark Zuckerberg is not yet even in his mid-20s, his résumé is a bit thinner than others here. Well, except for his first job as founder and CEO of Facebook, perhaps the most explosively popular social-networking company ever and the most high-profile Web 2.0 start-up. Mr. Zuckerberg created Facebook in 2004, while still an undergraduate at Harvard University, where he studied computer science. He brought the company to Silicon Valley before he had a chance to graduate from college, but managed to get a $15 billion valuation for the company anyway.




