Dennis Crowley, 33, and Naveen Selvadurai, 28
Their claim to fame: They founded Foursquare, which has been valued at $80 million.
Their blueprint for success: Foursquare allows users to alert their Facebook friends and Twitter followers where they are at any given time, encouraging everyone to check out cool places they've discovered. Selvadurai is a software developer and Crowley knows something about social media (he sold Dodgeball, a location-based social network, to Google in 2005). Foursquare, a combination of software and social networking, is based on a very human desire: to get out and see things and share experiences with people. Selvadurai created it simply because, as he told BusinessWeek, "I live in the East Village, which has so much rich history and so much to do, and I realized that I'd seen maybe 5 percent of it. I was looking for a way to get me and my friends to go out and do more things."
(AP Photo/Russel A. Daniels, File)