Backup your Firefox Extensions with FEBE
If you, like me, use Firefox on more than one machine and hate having to install extensions back and forth between them, then this is the right extension for you.
FEBE backs up your extensions, themes, and (optionally) your bookmarks, preferences and cookies.
I’m not sure why it doesn’t backup Firefox’s passwords, but I guess it’s for security reasons (or just technical). In any case, this extension just joined my list of “must get” ones for Firefox. Enjoy!