3. Digg: Kevin Rose
Entrepreneur Kevin Rose enrolled in the University of Nevada Las Vegas where he majored in computer science, but dropped out to code software. In 2004, the 27-year-old launched Digg, a social news Website, with just $1,200.
Since its launch, Rose has invested money in the launches of Twitter and Foursquare. This year, he—and the rest of his newest startup, mobile app company Milk—joined Google. His net worth has not been recently published.