YES PLEASE Money Balloons - a cool way to present money as a gift, esp for a young person (as opposed to a boring check in a card). I have a friend whose parents blow up a balloon and put a one dollar bill in it and have the number of balloons for how old their kid is on their birthday and then after they open their presents they can pop open the balloon and get their $. very cute.
This link has a ton of unexpected things to do with balloons. Definitely doing this for my birthday! Also put a message in a balloon and give it to someone so when it pops, they get the message!
Attach sparkly foam circles to balloon strings