This one requires a prize or two. The idea is to sell lots of helium balloons containing slips of paper with numbers on them. Draw a prize winning number out of a drum, and then instruct guests to pop their balloons to get at the number inside and discover if they've won the prize. This is a colorful and fun activity you can integrate into other events on this list. All you'll need is balloons, helium, ribbon, paper and a prize. If you can get a large crowd together, this can be an easy and profitable activity.