After graduating from Syracuse, Foursquare CEO Dennis Crowley worked at the tech firm Jupiter Research, and then Vindigo, a pioneering city-search service for PalmPilots. Online city guides were huge at the time, but Crowley found them boring. They never seemed to know about the cool places he and his friends were going--so he decided to build his own. He taught himself to code and developed Dodgeball, a mobile services company that sold to Google. Today, Foursquare has reinvented itself as a local search and discovery engine, distancing itself from the check-ins and virtual badges it had become known for.