This is the Solowheel, a briefcase-sized unicycle that allows you to zip around like The Gentlemen from the Buffy the Vampire Slayer episode "Hush." Here's a product description from manufacturer Inventist:
Externally, the Solowheel consists of a wheel and two foldable foot platforms. Internally, the inner workings of the Solowheel use gyro sensors, a 1000-Watt motor and a rechargeable Lithium-ion battery. All this technology is housed under a visually appealing, slim case with leg pads and a handle for easy carrying.
100% battery operated; leaning controls your speed. Lean forward to go forward and backward when you want to slow down. The highly efficient lithium ion battery recaptures energy when going downhill or slowing down. It has a two hour battery life and can be fully recharged in only forty-five minutes.
If I was an unscrupulous millionaire, I would purchase several hundred Solowheels and command my underlings to dress up as the Wheelers from Return To Oz.
[Via Core 77]