http://www.distrowatch.com/review-knoppix.html

Salient point made early in the review:

Knoppix is a "live CD" distro - just boot it and use it. You do need a CD drive of course, but you 
don't need a hard disk. The implications of this are significant. It means you have a portable 
Linux that you can take with you wherever you go. This can be used in a number of innovative ways - 
as a demo disk, as a rescue disk, as a way to use Linux at your local Windows-only Internet cafe. 
Some people even take a Knoppix disk with them when they go shopping for a new computer, a clever 
way to ensure that the hardware will be Linux compatible before you purchase it.

Brian Kelsay