An inside contact to a company (mentor or a parent) is definitely more effective than a cold call trying to explain who you are and what you do. Also like said before, making presentations to boards with lots of statistics about the power of FIRST is a good way to go. We also have finance packets we distribute at PR events that explain more about FIRST and our team, giving possible sponsors lots of background info. The one we use can be found at
www.mvrt.com under "News." Some large corporations like IBM and Lockheed Martin also give money if their employee donates time to become a mentor for the team, just something interesting you can look into. Right now we primarily rely on team members and corporate sponsors since our school doesn't allot any cash for us. Hope this helped.