[GeeTwo]

If you do crowdsourcing, look at piggybackr.com as the medium. It has the appropriate controls in place which allow minors to individually promote the campaign and receive credit for donations, while maintaining sufficient privacy standards. Also, have a specific goal/purpose in mind for each campaign, e.g. "to purchase a backup/spare control system" or "to fund travel to the xxx regional"; many people are more likely to give just as much several times per year when presented with specific fundraising goals as when all of them are just to "benefit the team".

As an FRC team, we have also had good success ($300 to $700 per weekend) doing demos or just setting up a table in front of local retail outlets. The venue doesn't so much matter as long as you get a lot of traffic: our two best were at a Boot Barn western wear shop and a Winn Dixie grocery store. Put the kids forward and be ready to chat with anyone who's interested (but not forceful). Bringing a robot is a nice touch but not essential if you bring a photo album or electronic photo frame with a slide show. Show the kids more than the robot(s)! Not only do these touches help contributions, it can also help you pick up a new team member or mentor.