This is a pretty cool invention that could be really useful for anyone who wants to save gas.

It's a wheel you put on your bike that allows the bike to run on a small engine.  It goes up to 20 MPH and gets 200 miles per gallon of gas.

You don't have to use it if you want to bike the old fashioned way, but it's a nice feature to have on your bike if you need to get somewhere faster and are worried about getting all sweated up.  Or if you just lose your energy on a long ride.

$400 isn't too unreasonable of a price tag either.