[jimnutt]

We let my (now 7.5 y/o) son start using a tablet when he was about that age. But it wasn't "his", we allowed it mostly in the car (we live in a rural area and it's a long way to anywhere) and limited the games on it. Now, it's a lot easier, with the Kindle Fire tablets, you can set up FreeTime which allows setting time limits for different things and can require stuff like reading books for an hour before you can play games. With regular Android tablets, you can set up a limited user and control what apps are accessible to that user, it doesn't enforce time limits, but simply taking the tablet away from the child works pretty well for that :). He's getting his first real computer this year (an older Dell laptop) with Linux on it, I'm planning on teaching him the bare essentials and letting him figure the rest out himself (and doing some filtering at the router for that MAC address).