Cool FireFox Add-Ons

[VoX]

There are many FireFox add ons out there, so what ones do you use and what do they do?

Here are some of my more useful ones:

Adblock plus (https://addons.mozilla.org/en-US/firefox/addon/1865) - Removes pesky adverts.
Piclens (https://addons.mozilla.org/en-US/firefox/addon/5579) - View your images in stunning 3D!
Fasterfox (https://addons.mozilla.org/en-US/firefox/addon/1269) - Some performance tweaks for FireFox.
IE Tab (https://addons.mozilla.org/en-US/firefox/addon/1419) - Use IE within FireFox for those pesky IE only sites!
ColourZilla (https://addons.mozilla.org/en-US/firefox/addon/271) - Find out the colour code without having to take a print screen!
MeasureIt (https://addons.mozilla.org/en-US/firefox/addon/539) - Seen the ideal sig/banner size? Measure It easily

[Calneon]

Downloaded the first 2, they look pretty awesome :D.

[Chazlene]

The bottom two seem like they'd be quite useful to me, might install them. I use Adblock Plus, as well as Flashgot (http://flashgot.net/), a download manager for Firefox.

[VoX]

Ooops I fotgot DownThemAll (https://addons.mozilla.org/en-US/firefox/addon/201) - A download manager that lets you split the download to increase speed!

[Mr.Big]

Also downloadhelper lets you download from most sites flash videos youtube etc...