Lot's of Add-Ons that I have used at some time or another that picked my interest
Adds zoom and rotation functionality for images...
Collector's Note Very Handy!
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.
Save time by speeding up repetitive tasks. Get faster, parallelized downloads, see definitions, auto-load the next page, improve searching, and more. FastestFox will dramatically enhance your productivity!
UnPlug is an extension which lets you save video and audio which is embedded on a webpage - it's a video download tool.
Block web pages containing pornography or any other type of material based on keyword lists.
Cookie Monster provides proactive cookie management on a site or domain level basis, including 3rd party cookies. Via the status bar, it provides easy access to enhanced cookie functionality, while doing so in a non-intrusive manner.
Collector's Note When configured correctly, very helpful
Useful tools for the nightly tester.
View and manage downloads from a tidy statusbar - without the download window getting in the way of your web browsing.
Thanks Tekzilla for your awesome review! Click here to see their video: http://youtu.be/BUDqWrJ-Vao
Allows you to hide almost anything via context menu 'Remove Object'.
Open IT Online allows you to open documents and images online without the need of any software to be installed. It supports Google Docs, Zoho, View Docs Online, Vuzit to edit/view documents and Snipshot, Pixlr, Sumo Paint, etc. to edit/view images.
An extension that allows for the use of dynamic commands in Firefox.