Dennis Crowley and Naveen Selvadurai, Foursquare founders

Photo portrait session with co-founders of social media website Foursquare, Naveen Selvadurai and Dennis Crowley, in their shared office in New York, USA, 5 August 2009. Foursquare, which allows users to stay connected to friends and explore a city, has been dubbed "the next Twitter" by an influential tech blog.