SLAX (pocket OS) now comes in modded flavors, including Popcorn, Kill-Bill, and Professional. Down the road we'll see Hacker and Frodo mods too. SLAX is based on the Slackware Linux distribution and is downloadable as an ISO image.Check it out
At OSDir we waffled but finally decided to go with the Professional version for our screenshot tour of this great Linux distribution. See SLAX in action here.
OSDir has posted a screenshot slideshow of SLAX