

A swimming pool and golf aren't two things that you would normally think go together, but I have to say after playing this myself, it's pretty fun. And the best part is you get to practice your chip shots while the kids shag the balls for you.
The Aqua Golf Game is a pretty simple idea. It consists of a floating "green" with a flag that goes in your pool, a mat of turf to hit balls off of, and small velcro covered plastic balls. It's not a kids game per se (there is no kiddie golf club or anything), but if you can convince them it's fun, their job will be to go get the balls that inevitably don't hit the green.
Also, I would definitely recommend this version, and not some of the other versions out there. In this one the green is a good size and it comes with the mat to chip off of, which is essential for a pool deck.
Aqua Golf Game, available in lots of pools stores, or for $59.99 from Poolcenter.com