Square's Jack Dorsey: Lessons Learned from Twitterbr DEMO - Hyatt Regencybr Backed by expertise from Twitter startup veteran Jack Dorsey, Square was launched in February 2009 to create a simple platform for payments using mobile technology.What forces are driving movement to mobile payments? What will it disrupt? Where is it headed? And what does it take to launch a company with huge viral appeal? Don't miss this revealing conversation with the pioneer in this space.