Well, a bit of ChiefDelphi forum searching (hint hint ; ) turned up this:
Team 857's "kiwi" drive, with pictures and drive test video:
http://stuweb.ee.mtu.edu/~alkrajew/FIRST/
There's also an omniwheel entry in the FIRST CAD library:
http://www.firstcadlibrary.com/pages...al%20parts.asp
And Team 122 has made omniwheels for the 2001 game:
http://www.chiefdelphi.com/forums/sh...0&postcount=12
and so did Team 111 for the 2002 game:
http://www.wildstang.org/
Here is a post from Patrick of Team 639 where he lays out his omniwheel design:
http://www.chiefdelphi.com/forums/sh...5&postcount=12
and a picture of it:
http://www.chiefdelphi.com/forums/at...achmentid=1307
And, from the combat robot community (Gasp!) :
"Y-Chromosome" by Team Radicus, with homebuilt omniwheels, and extensive build reports and video:
http://www.teamradicus.com/bots/yc1/
Note that Tony drives YC with hobby radio gear, by sheer hand-eye coordination. Now, for a combat robot with a spinning weapon that covers 300 of its 360 degrees of approach, this is not a big problem, but for FIRST precise maneuvering some fancy programming would be needed.
There is also a 340-pound omniwheel combat robot, Alcoholic Stepfather. He uses an IFI robot controller, a gyro, and a custom program with a feedback loop to make him driveable. Here are a few of my pictures:
http://www.uiproductions.com/pteryxx...-AStep_vs_Toro
http://www.uiproductions.com/pteryxx...-Omnihalf.html
Here is a store-bought omniwheel, used as a caster under the nose of a 220-pound combat wedge:
http://www.mcmanis.com/chuck/Robotic...right-omni.jpg
And here's a company that makes and sells such wheels:
http://www.omniwheel.com/omniwheel/omniwheel.htm
Hope this is of some use - Piece, Pteryxx (Team 1301 and Western Allied Robotics)