David Karp, the 26-year-old founder of Tumblr, sold his site to Yahoo! in an all-cash deal yesterday for $1.1 billion. The high school dropout has undoubtedly done well for himself, the deal making him one of the wealthiest and most successful techies under the age of 30. The native New Yorker will stay on as CEO and we're excited to see where he takes the website next. Check out our Daily Style Phile of Karp to find out more behind the scenes facts about the founder.