I made these free paper models a while ago for me and the kids to have some fun, so thought I'd post the link here as well:

http://homepage.ntlworld.com/calvertfil ... robots.htm

I've used famous designs (no copyright infringement intended - these are free and made for fans to have fun with) but you could also design your own. If you put radio control micro cars under them they fight really well (see the videos).

Have fun!