The Tacoma Robotics Society in Tacoma Washington is putting on a sumo robotics competition with sumo-bots made from hacked together stuff.
Here is some pictures of my robot for the competition: http://www.flickr.com/photos/pdavenport/5097737575/in/set-72157625276503522/
We would love to see you there. Here is an info link: http://www.tacomarobotics.org/
