We've seen community bike services before, but the Social Bikes setup coming to NYC puts a unique twist on the idea: the whole system is built onto each bike, allowing you to leave it anywhere when you're done with it.
Rather than having you pick up and drop off bikes from central base stations, the Social Bike System offers bikes with big GPS units equipped with a cellular device and a lock. You use your phone to track down the nearest free bikes, unlock it using said phone and ride away. When you're done, you just lock it back up somewhere else for someone else to take.
There will be base stations, too, but the ability to leave a bike anywhere makes this much more convenient. It's a cool system, one I'm excited to try out when it comes to my fair city this fall. [Social Bikes via Gadget Lab]