"Today at the COP 15 Climate Change Conference in Copenhagen, M.I.T. students introduced the technologically advanced Copenhagen Wheel. In addition to including various sensors and Bluetooth capability, the tire stores kinetic energy from braking for a later burst of speed.
The makers of the Copenhagen Wheel from M.I.T.'s SENSEable City Laboratory claim that the new features mark the advent of "Biking 2.0," a new era based on smarter bikes and easier rides. The wheel is certainly a step in that direction; it includes sensors for detecting distance, speed, direction, all of which are beamed via Bluetooth to the rider's iPhone. The wheel also includes a built-in lock that sends the rider a text if tampered with." Gizmodo