An Interview With Dennis Crowley, Co-Founder of Foursquare on Startups, Mobile, and Being King

I recently tweeted this question. Out of the tens of responses I got to the question “What services do you use daily” almost half of them included Foursquare, along with Gmail, Facebook, and Twitter. If you are not familiar with Foursquare, it is the undisputed king of location-based services. The concept is simple. You “check in” to locations and let your friends across the Web know where you are.