I purchased a *ist DL with some lenses from Ebay for pretty cheap not too long ago. I really only wanted the lenses, so I gave the *ist DL to my seven year old son. I set him up with an account here, and now we go out together trying to find good pictures for the weekly and monthly contests. It gives us something to do as a family, that gets us out of the house. The *ist DL is perfect for him, because he can just set it to auto, and focus on the basics (the manual features will be there when he is ready). I got him two lenses (a Quantaray 28-90mm and Quantaray 70-300mm) that are cheap enough for me not to care if they get damaged by accident. He also has a little sling pack to carry around his gear in. He actually gets some pretty amazing pictures with the camera, and some unique perspectives because of his height and the level he is shooting from.
I hope you and your child have as much fun as I am having with my son.
Here are a couple pics of him on one of our outings.