Self-balancing 2-wheel car.

Very cool. 

http://youtu.be/SLHvs7LA23w

Dramatic demonstration of it's balancing ability when it's yanked by a pickup at 1:16 in this video: 

http://youtu.be/O1aAmWim838

Reminds me of the two-wheeled DARPA-challenge motorcycle, though a lot sleeker. 

http://youtu.be/6CYGT97i8qU