The Ryno is a one-wheeled beast of an invention, manufactured and sold by Ryno Motors. It combines the technical sensibilities of the Segway with the look, feel and, quite literally, half the badass-ness of a motorcycle.
The Self Balancing Electric Unicycle - Hammacher Schlemmer. This is the briefcase-sized electric unicycle that keeps a rider perfectly balanced at all times with gyroscopic sensors. Equally suited for urban commuting and suburban recreation.