I just noticed that version 2.0 of SliTaz, a light-weight GNU/Linux distribution weighing in at under 30 megabytes, was released a few days ago.
If you are looking for something small to run on an older computer, SliTaz is definitely a worthy contender to look into. Do not let the small size of the ISO fool you. It contains more than enough software to get you going. If you need something that isn't installed by default, you have access to their software repositories via the tazpkg package manager.
I have been running it on an old 500MHz Compaq Presario 1200-XL111 for over a year now (using their cooking versions) and I couldn't be happier.
My congratulations go to the SliTaz team for yet another fine release.
Anyway, Lets get on to the screen shot tour:
SliTaz 2.0 is available for download at: http://www.slitaz.org/en/