Have some glitter sitting around the house? Why not use it to decorate your balloons? Just use some glue to coat one portion of your balloons and then fill a tray with glitter. Next, roll your balloons in the glitter, and you're done. Admittedly, this one could get a bit messy, but it's still a great activity if you want to get kids involved with helping you decorate for a celebration.
You can use pretty much any type of glue you have on hand, but if you're not using a glue stick then you'll probably want to wear gloves for this one.