Copenhagen wheel

Smart, responsive and elegant, the Copenhagen Wheel is a new emblem

for urban mobility. It transforms ordinary bicycles quickly into hybrid e-bikes that also
function as mobile sensing units. The Copenhagen Wheel allows you to capture
the energy dissipated while cycling and braking and save it for when you need
a bit of a boost. It also maps pollution levels, traffic congestion,
and road conditions in real-time.

http://senseable.mit.edu/copenhagenwheel/

http://www.nytimes.com/2009/12/15/science/earth/15bike.html?_r=1&scp=1&sq=copenhagenwheel&st=cse