Portable Firefox is a fully functional package of Firefox optimized for use on a USB key drive. It has some specially-selected optimizations to make it perform faster and extend the life of your USB key as well as a specialized launcher that will allow most of your favorite extensions to work as you switch computers. It will also work from a CDRW drive (in packet mode), ZIP drives, external hard drives, some MP3 players, flash RAM cards and more (Note: It will not run from read-only media like a CD-R, but Portable Firefox Live will). This grew out of a mozillaZine forum topic (now split in two: original, followup) back in June of 2004. Any comments or questions can be directed to the current Portable Firefox mozillaZine thread. You'll find me in the forums as CritterNYC.