Dennis Crowley (Silicon Valley, USA) Foursquare co-founder & CEO An American Internet entrepreneur best known for co-founding the popular social networking sites Dodgeball and Foursquare photo by: Stephen Gurie Woo www.stephenwoo.com special thanks : Leica Camera AG (North America), Downtown Camera (Canada), Sofitel Redwood City #stephengwoo #stephengwoophotography #leica #leicaportraiture #denniscrowley #foursquare #siliconvalley