Well folks I think I created a Portable Firefox for Linux.
It works, I tested it on my USB stick and it was so super simple.
If anyone wants to try it out (and if the devs want to tweak it and add it to the list of apps) below is the download link **NOT SELF PROMOTION - IS A WORKING PORTABLE APP FOR LINUX THAT I'VE YET TO SEE DONE**
Also note, This was tested so far on a USB stick and hard drive on Linux Mint 3.1
[link removed by moderator JTH due to licensing]
Just decompress and run startfirefox.sh and be sure to give me feedback, bugs, what systems it runs on, etc.