Age: 26
Company: Facebook
Net Worth: $4.9 Billion
What's the Deal?: He thinks he's Bill Gates, Steve Jobs. Actually, he's a little bit of both. With Facebook boasting over 500 million users, it's the biggest social network in the world. Its $23 billion market valuation put him at #35 on Forbes 2010 "400" list, higher than Apple's CEO. He may be painted as a geeky asshole, but his recent $100 million donation to Newark's public schools makes him cool with us.