Oh right.
Did a search on google images for "robot wheel" and I think its a coupla pages in.
/edit images.google.com/images?q=+robot+wheels&svnum=10&hl=en&lr=&ie=UTF-8&start=80&sa=N
( ,
Fri 28 Feb 2003, 22:29,
archived)
/edit images.google.com/images?q=+robot+wheels&svnum=10&hl=en&lr=&ie=UTF-8&start=80&sa=N