In terms of cool ideas for bikes, this old-school Electra bicycle with a pulse jet engine is up there with the best! Robert Maddox idea involves an old school Electra bicycle and a pulse jet engine (otherwise known as the German V-1 Flying Bomb)
The video below shows this cool bike in action and it isn't just an idea now. He's selling them!
Robert test riding bike:
Cool eh! and you know what else is cool! Robert sells them!