In perhaps the most famous entrepreneur story of the 21st century, Mark Zuckerberg and several classmates founded Facebook from a Harvard dorm room in 2004. Facebook now has more than 1 billion users worldwide, and Zuckerberg himself is worth about $30 billion, making him one of the world's richest men.
Photos: Striking it rich in tech
Peter DaSilva/The New York Times/Redux
Striking it rich in tech —
A number of entrepreneurs have parlayed tiny tech startups into millions, or even billions. The latest to hit the jackpot: WhatsApp founders Brian Acton, left, and Jan Koum, who sold their mobile messaging service to Facebook for $19 billion in cash and stock.