Green wheel turns pedal bike into electric hog

This is really cool – a self-charging electric wheel that you can attach to any bike. (presumably 26″ wheels) You can also add one in front and one in back for dual wheel drive. Although how you would throttle that is unclear. I would love to put one of these on the back of the Xtracycle for a little extra oomph and speed.

Hopefully these will be out soon and not outrageously expensive.

Green wheel turns pedal bike into electric hog
Discovery.com via msnbc.com