Bubbles. They are so simple, yet so much effective. Children love them. The more, the better. All you need is a bucket of soapy water, a man who does the job and a big square with lots of children. I had all three yesterday. Children are great. When they are drawn into the game, they forget about the outer world. I wanted to delve into their world for a while. It was only a few minutes, but it was worth it.