When the kids were really small, we relied on the kiddie pool in the backyard to keep them entertained and cooled when it was really hot.  Last summer, I could see that the kiddie pool had become boring, only serving as a place to fill water guns and buckets of water.  Which were good things, but it no longer provided the hours of entertainment I was looking for.  One hot day last summer I bought a slip and slide, and so far, the entertainment value is holding up just as strong as the orange and blue plastic.