These boards are really great! Thanks to all for the wonderful ideas. Here are some more.
I'm co-chair of solicitations for our school auction. We had several Mom's go onto the local Chamber of Commerce Website and get all the members' contact info. Then we sent them ALL a letter. You'd be surprised at what you will receive if you just ask! Also, ask them for specific items. Instead of just a gift certificate from Cold Stone, could they host an ice cream party for 12? Get creative! We're getting clown cones from Baskin Robbins, homemade invites from a parent, and a balloon bouquet from a local party store = instant birthday party!
Other big sellers:
Parties hosted by families (Indian dinner, Backyard BBQ, Murder Mystery)
Vacation homes/packages (donated by families that have them)
Sports lessons for the kids (tennis, golf, swimming, etc)
Children's artwork by classroom brings in a LOT
Also, because we're in Napa, we get TONS of wine