Although the concept isn't new and various monocycles of this kind had already been built, it's unlikely you'll find one for sale, even in special stores. That's what happened to british designer Ben Wilson, who, consequently, decided to build his own one-wheeled vehicle, which he simply named Monowheel.
Like many others, the Monowheel is powered by pedals, however, in this case, the rider sits within the wheel, in an almost lied down position. It's not a very confortable position, but this is not an utilitary vehicle of any kind, merely a demonstrative one, ordered for the "XXI Century Man" exhibition in Tokyo.