Remember the monocycle that was an image of the day a few months back? Built by a gent named Kerry McLean? It turns out not to be a new idea at all! <a href="http://www.dself.demon.co.uk/motorwhl/motorwhl.htm">This page</a> shows a number of different concepts around the same idea. Turns out people have been building nutty vehicles since the first engine. Who'da thunk?