I agree, a picture of the bot in question would be nice so we know what you could potentially lighten or cut.
What are you using for your hopper? It doesn't have to be solid, it could be as simple as some cord (
http://www.chiefdelphi.com/media/photos/32582?)
How many wheels do you have? I know this is drastic but you could cut from 6 wheel down to 4 wheel.
Barring any of those, what are you putting over your electronics? I know 397 probably won't put too much over them this year. Actually last year we left them exposed in the middle of our robot (right under our launcher) and never had a problem.