The gyrowheel would make it so that anyone learning to ride a bike — or just keep any ol' bike upright — wouldn't need training wheels to keep from falling over. The gyrowheel replaces the front wheel and contains a battery-powered, spinning disk inside of it, which in turn generates a gyroscopic precessional force and helps stabilize the bike. It should keep a bike upright in the face of wobbles, and the folks at Gyrobike claim that it teaches better riding practices, besides.
A 12" version of the gyrowheel is due out in December, with a 16" version landing next spring.
Check out a video on how the gyrowheel works after the jump.