DS8 got his own computer this year, a desktop in the kitchen.
If you aren't averse to it, I would suggest a Mac of some sort because you don't even have to worry about virus protection that way -- Macs are far less likely to pick up a virus from the sorts of things that kids download.
We started with a Mac Mini that my work was upgrading from, but it had an unfortunate little-sister accident, so he's just got a regular PC now. I have no doubt that one too many Mario screensavers or Tetris demos will cause us to have to wipe it from time to time.
