How about a free computer?
Here’s how you do it...
Get that old old 486 computer out of your basement.
wipe the hard drive
install DSL (Damn Small Linux)
Tada! free computer.
http://en.wikipedia.org/wiki/Damn_Small_Linux
Or you could remove the innards from the case and then...well ... see #7.
Relative gave me an old computer last week. Hard drive was bad, pitched it. I saw a post a while back about Pendrive Linux so I found it and installed Lucid Puppy on a SD card in a USB adapter.
It worked slow so I cleared off my external hard drive and installed Puppy from the memory card. It works but it tends to freeze up if trying to view youtube or anything that takes memory.
Kubuntu was recommended to me, I’d like to get that on the external drive but no luck so far. Kubuntu live CD even fails. Must need a hard drive.
If I have time next weekend, might try DSL.
Better yet. Find a cheap used p4 or AMD on Craigslist. Install linux. Done.