I saw a this thread (http://www.chiefdelphi.com/forums/showthread.php?threadid=50098) and thought I would post some pictures of my own Kiwi bot I built about a year ago that has just been sitting in my closet. I used a big 40 tooth gear as the “hub” for the 8 roller omniwheels. I found that a 6 roller omni was a bit too rough and the fairly weak RCX motors I have were having trouble moving the bot around, so I upgraded to 8 rollers. It still has trouble moving around if the batteries are drained at all, but with a fresh set of double A’s, it cruises just fine.
Now all you need to do is get an NXT and recreate it with that. Nxt motors are more powerful, and with encoders built in I think that just might show up at an FLL competition next year.