FEBE (Firefox Environment Backup Extension) allows you to quickly and easily backup your Firefox extensions. In fact, it goes beyond just backing up -- It will actually rebuild your extensions individually into installable .xpi files. Now you can easily synchronize your office and home browsers.
CLEO (Compact Library Extension Organizer) is a Firefox extension that works with FEBE to package any number of extensions/themes into a single, installable .xpi file.
OPIE (Ordered Preference Import/Export) is a Firefox extension that allows you to import and export your installed extension preferences. This is useful when installing extensions in a new profile, or synchronizing multiple Firefox installations.
MozBackup allows you to backup and restore bookmarks, mail, contacts, history, extensions, passwords, etc.
Massive Extender is a Firefox extension, you can install all your add-ons in one batch.
