One of the fundraisers we do over the summer to help fund our off-season is a Bottle and Can drive. Basically, go door to door asking for bottles and cans, and turn them in for the money. We got about $750 from this.
I would assume this is a bit location/time-orientated but during the summer also, there is a big Arts and Apples festival held in the Rochester park in our city. During this art fair we are allowed to use the parking lot of our school district's administration building to charge $5 for parking for the day (it's a three day art fair).
With both of these, and member contributions that help pay for things like transportation, we have been able to support ourselves during our Fall/OCCRA season.
Your team could also start selling FIRSTGreen E-WATT Saver bulbs, although I don't really know much about fundraising with them.
http://www.usfirst.org/roboticsprogr...n-e-watt-saver