Knoppix is a lightweight Linux distro that is anything but light in its features and functions. It equals or exceeds the performance of all the desktop varieties I run in Ubuntu and Linux Mint. It also could easily replace the portability on a stick I get with Puppy Linux. Knoppix, much like Puppy Linux, provides a fully functional Linux distro that boots from a DVD or USB drive. Both save user settings and downloaded software added to the mix. 
