Make "Sponge Bombs" and gather some neighbourhood kids (and adults) together along with a few buckets of water for a fun water fight. unlike water balloons you won't have pick up a ton of shriveled latex balloon pieces afterwards.
Homemade bath crayons - Buy some glycerin soap at a craft store. Melt it in the microwave, add food coloring, and pour into a mold. I used an ice cube tray. Takes about an hour to cool completely, then pop out of the mold and you have crayons!
The Great Water Balloon Alternative: It's that time of year again - time for water games without the broken balloon mess to clean up! And without having ALL of that time into making the 100 water balloons for 3 minutes of fun!