Here's a few more distro sites:

http://www.distrowatch.com/dwres.php?resource=cd
http://www.tuxcds.com/
http://www.slackware-live.org/
http://emergencycd2.sourceforge.net/
http://morphix.sourceforge.net/modules/mydownloads/

there's also knoppix and most recently clusterknoppix which utilises openmosix to run a thinclient network.

Kwi