Here is some pics of our cart from this year... It was pretty fun to build, and really got our team noticed and everyone in the city was like, "oh yeah, your that team with that cart!" so it was pretty sweet for demos and stuff...
http://www.chiefdelphi.com/media/photos/31254
http://www.chiefdelphi.com/media/photos/31247
Big thing to remember is how you are going to power everything, we used a Hybrid Battery out of a new Tahoe, but you may want to find something of the sort, because power is an important issue if you are on the move.