So far, it appears to be a design sketch as opposed to a working prototype, but this motorized unicycle from Bombardier is just too cool for words:

Vaguely resembling a sporty motorcycle, the uni-wheeled Embrio uses electronic and hydrogen-fuel-cell technology to help its driver zip around obstacles. A system of gyroscopes keeps it upright. In standby mode, a pair of extra wheels deploy jet-plane-like landing gear to increase longitudinal stability.
And, I might add, a control system engineer's dream!
Posted by elkaim at December 1, 2003 03:51 PMthis has got to be the koolest thing ive ever seen, if it comes out at a reasonable price, im definately getting 1