NimbleX is small linux distribution based on Slackware. It can be run from CD, USB or network enviroment and it features full desktop enviroment, that fits on ~200MB ISO image. It was also possible to generate custom ISO images via offcial page that included specific backgrounds, preinstalled packages and more. The last stable release (2008) was released in July 2008 and the last beta version(2010) was released in April 2010.
Links: Homepage [archived]
Note: default password is root/toor