I raised quite a lot of money one time when I was allowed to sell otter pops (yuck and lots of plastic trash aside) to the students after their lunches. The kids loved it and bought them as fast as we could sell them. Spring in AZ. I realized that I could make a lot more money selling otter pops than I could teaching (really!) but I wouldn't get to die knowing I had made a valuable contribution to the world. Great fundraiser, and my students selling had as much fun as the kids buying, I think.