I love this idea from the Crafts Dept.
for using water balloons and either plastic coffee stirrers or wooden skewers to creae an inflatable balloon cake topper. Buy a small bag of water balloons (available at most drugstores this time of year or year-round at toy stores). Blow up the balloons (with your own hot air - no helium needed) and slip a coffee stirrer (wooden or plastic) or wooden skewer into the knot as you tie it. Stick the skewer into your cake or cupcakes for a simple and cheerful birthday celebration. Use one balloon for each year, as you would with candles on the cake.