Interesting new tech if you're into bikes: the Copenhagen Wheel is a disc-shaped module that can be retrofit onto almost any bike. It's:
... an electric pedal-assist motor fully contained in the oversized red hub of an otherwise normal back bicycle wheel. Inside that red hub is a delicately crammed array of computing equipment, sensors, and a three-phase brushless direct current electric motor that can feel the torque of my pedaling and add appropriately scaled assistance.Sometimes you do still have to pedal though.
Replace the back wheel of any bike with the Copenhagen Wheel and it's instantly an electric bike—one that not only assists the rider but senses the surrounding topography and can even collect and share data about environmental, traffic, and road conditions. First developed in 2009, through a partnership between MIT's Senseable City Lab and the City of Copenhagen, the wheel is now in its first stages of commercial production. By the end of 2014, thousands will be shipped out to fulfill pre-orders around the world.