I love the idea of giving kids access to the net on an old computer. Even better would be to simulate a 44k modem over wifi. This makes it possible to load anything, but you have to really want it, and you may even have to plan ahead (gasp!) before downloading something. It also inherently biases the kid to learn more about the local machine locally, which I believe is the key to growing a healthy adversarial relationship to computing devices. If you make the usual way of getting entertainment hard (e.g. youtube) my hope is that they will create their own entertainment (hacking the machine).