[Zanta]

Neat! I built a little mobile robot that uses omni-wheels[1], a related style wheel. Build report here[2] (forgive the lousy website, I'm a mech guy just starting to learn software)

The wheels allowed some neat driving tricks, but it also made it really difficult to drive in a straight line. You don't get the normal tracking behaviour that wheels give you, and differences in traction from wheel to wheel also tend to distort your course. Adding a gyro for use in a closed-loop angular control system really helped this a lot.

[1] https://en.wikipedia.org/wiki/Omni_wheel [2] http://willbeattie.ca/Projects/Twitch/Twitch.html