Ryan Rzepecki's idea for a Social Bicycles System puts the power of finding and unlocking bikes in the palm of the hand. By adding a locking mechanism to the back wheel, bikes don't have to be locked at a docking station, and can be unlocked by system users with a simple on-phone application.
"A few advantages: You don't need docking stations, a la B-cycle systems. The bikes can theoretically be a lot cheaper than the $3,500 (!) cycles in the world's first citywide network in Paris. And, as with any of the fast-spreading bike-sharing networks, you get mobility without needing a car."