OK, I'll admit that this self-stabilizing bike is clever: it's kind of a Segway turned sideways, using gyros to detect if it's off-balancing, and adjusting the steering automagically to compensate. It's also a standard electric bike, so it propels you along without needing any annoying foot-power: very 21st Century indeed.
Apparently it's quite tricky to get a bike to balance, since steering and such requires a degree of off-balance maneuvering...but the team at Keio University in Yokohama has managed it and their prototype easily manages 2.5 meters per second.
They're working on making it able to deal with uneven road surfaces, and ultimately they want a zero-speed stable bike, since "Many bicycle falling accidents happen when elderly people stop a bicycle in a crosswalk, and so on." Great. Though, I'm going to suggest a lower-tech and greener approach: A third wheel. [Physorg]