On the subject of small computers (in this case NOT old ones), i've got access to a Asus eeePC - the 701SD version with replaceable 8GB SSD and upgradeable RAM. And
of course I had to tweak it!
So - once again - I installed Debian on the thing. With 8GB storage, a relatively modern CPU (Celeron@600MHz) and lots of RAM, it was no problem at all. Enter KDE, Compiz 3D-desktop and a pile of different goodies.
You'll be tempted to think this is just a toy - priced at 200 USD it won't appeal for much more, right? A TI-89 calculator is higher priced...
But oh no

Its miniscule size alone will draw attention to it, when casually dumped on a cafe-table downtown. Behind me, i hear a snicker from people carrying 'real laptops'. These guys are almost guaranteed to run Vista on expensive hardware, thinking the 701 is a toy - and so the scene is set.
Pop up the lid, fire it up, listen. Behind me, the snickering changes tone; 'Huh - what's that?' Hook onto the cafe hotspot. Grab a local news site, twirl the desktop-cube. Pop up another site. Twirl. IRC. Twirl. Check my mail. Twirl - back to news. Read, enjoy my coffee, listening to the background noise which follows exploding menus, windows folding in funny ways and whatever i choose to do.
Great fun! I do this partly to grab my mail, partly to have fun.
Sometimes people come up to me and ask about the 701. Then we'll have a nice chat about the evolution of computers. I try to casually mention the 'Ubuntu' brand name - to point my newfound friends in a productive direction. We have some more coffee.
Never any mention of 'toy'...