One really creative and functional way to use balloons at your party is to freeze water balloons and then use them instead of ice to keep the drinks cool. It should also be less messy since the ice will melt inside the balloons.
Chronicles of a southern scrapper has a balloon wake up idea as well. She suggests writing messages on balloons about what you love about the child. She also suggests having a balloon for each month the child is old. So every year there are 12 more balloons.