Last summer our team did a few fund raisers and car washes. In the past we have also gathered up any of the team members junk and have had a yard sale because one mans garbage is another mans treasure. We have done a yard sale/car wash combo at one site. Hitting two birds with one stone kinda thing.
We served lunches to the students who were in summer school, we did a concession stand for the basketball team who had an off season practice at our school, we did our kids camp, which outreaches to the kids in our community to help them better understand science, math, and technology, we have done robot demos, of course off season competitions, like IRI, and many other things. I believe that the summer time is the perfect time for teams to fund raise because it doesn't get in the way of any of the build time. Also you could always start on your web page, chairman's award submission, Woodie Flowers submission, and entrepreneurship award.
I hope this helped and good luck with any of your future endeavors.
