Naval Ravikant and Babak Nivi
Entrepreneurs Ravikant (shown here) and Nivi created AngelList in February 2010 to help open up the clubby world of startup financing. The site has become a sort of LinkedIn for entrepreneurs and investors looking to connect. To date, more than 500 startups have successfully used AngelList to land funding from some of its 3,000 member-investors.
In 2011, AngelList quintupled its volume. It's also enabling new startup hubs around the country. A map of startups and investors connected through AngelList lights up not just Silicon Valley and New York, but Florida, Oregon and Arizona. Plenty of big VC shops--Kleiner Perkins Caulfield & Byers and Andreessen Horowitz among them--now use AngelList to hunt for deals.