Ok, as of old hardware, we have some choices, depending on what works...
The classic is to install Debian from this: http://www.debian.org/CD/netinst/ and then install Fluxbox, Rox-Filer, Opera etc...
But nowadays, Absolute sounds good for old PC's : http://www.pcbypaul.com/absolute/index.html (it's Slackware, it's fast)
As well as AntiX, it's a live-cd based on Mepis: http://antix.mepis.org/index.php/Main_Page
Of course, the good ol'classic DSL is a must , to test old stuff: http://www.damnsmalllinux.org/
But I enjoy having my Puppy CD, very efficient: http://www.puppylinux.com/


