Segway's Centaur Concept Edit
The Wheelie Machine

Segway has released a cool 4 wheeled toy that makes it easy to do wheelies and 360s.  The video makes it look ultra fun!
From Giz Magazine:
Segway’s Concept Centaur took centre stage today when Michelin announced its new TWEEL combination tyre-wheel. The Tweel was shown fitted to a Segway, an iBOT and Project Centaur, indicating for the first time from the company that the machine dubbed “The Wheelie Machine” has a commercial future. The Centaur is a lightweight, four-wheel concept vehicle combining the company’s proprietary gyroscope-based dynamic stabilization technology with advanced propulsion and suspension systems, and an intuitive user interface to create a unique four-wheel device that is easily controllable on two or four wheels. That’s right, you’ll be able to wheelstand out of sight the first time you ride it.