If you're racing down the street on a bike equipped with a speedometer, you're well aware of how fast you're going. But who cares about that? What about the people you're passing? Don't you want to rub in their faces how fast you're flying down the street?

That's just what this Speed Vest does. Equipped with electroluminescent wiring on the back and wheel speed sensor, it displays a bright numeric readout that states just how fast you're moving in no uncertain terms. It runs on a 9-volt battery for six hours, which is plenty of time to really show off how fast you can get going down those hills.

Speed Vest, via Oh Gizmo!