Sucking wheel: The opposite of a good draft

This has been floating around the interwebs for a week or so, and it got buried on our desktop. Still, the main thing that occurs to us is what a wide berth pedestrians and automobiles would give you if you had a large, razor-sharp fan blade spinning at several hundred RPM on your back.

We foresee a whole line of propeller-equipped messenger bags and backpacks designed not to push you forward, but to keep the suckahs off your wheel.