I gave my 6 y/o son his very own first lap, to use for school, an old Travelmate 290 with 512 RAM and a 40G HD, that we had decommissioned at work, and I was lucky to find.

I handed over the lap to the kid, and a Ubuntu 9.04 LiveCD and told him to put in the CD, an read on... after a couple of hours, he had it up and runnig, and it took him the rest of the week (considering we limit his time on the computer) to have it updated to 10.04, and installed google chrome browser.

Now, after a schoolyer of use, he even has a preference over the Windows PCs at school, because Ubuntu is, in his own words "Waaaaay cooler"