The Bike Computer is your personal on-cycle data processor. So much more than a speedometer, it shows your speed, but also your distance travelled, calories burned, top speed reached, direction and long and short-term averages. It measures the temperature, honks a little buzzer and controls LEDs to light your way and stylize your ride! Totally open-source and hackable, the bike computer is built on top of arduino so you can program it to analyze your biking data any way you like. The bike speedometer is designed to be easy to attach and detach so it will work nicely with NYCs ill-fated, though hopefully forthcoming, bike rentals. Powered by three AAA batteries or lightweight, rechargeable lithium.