This is a modified version of the Firefox Portable. It's slimmed down, and I've got rid of a load of crap you just don't need. The updater is completely gone. If you wanna update, do it manually. The version is currently at 188.8.131.52 - which will be ample for at least a year. It's small and compact and most importantly it WORKS.
I also made it with IETAB so you can use the IE rendering engine inside the browser and of course Flash Player.