NEWS FOR YOUR NEXT WATER BALLOON FIGHT. Here is an article about an invention by a Texas father which will enable filling 37 water balloons in twenty seconds. (link via Marginal Revolution)
In our experience, there was fun in preparing the water balloons for a fight. More helpful would be an invention to help in picking up little scraps of balloons after a fight (Mary Jane worried that scraps of balloons would be dangerous for wild animals or birds that ventured into the yard.)
I mentioned this problem to Annalisa, and she told me that giving a prize for the most balloon scraps gathered is supposed to work.