For those who have everything: The Gyrowheel

The Gyrowheel “aims to replace traditional training wheels” by swapping out the standard front wheel of a child’s bike for one containing a spinning disk that helps the bike to self-stabilize. “The force created when the disk is turned—via a rechargeable battery—is powerful enough to hold a wheel upright at very low speeds.” The result? Kids can learn to pedal and then, gradually, ratchet down the power of the Gyrowheel and learn to balance all on their own.
Price: $99.95
Contact:
TheGyrobike.com
Source: Wired.com