USEFUL ADDONS FOR MOZILLA FIREFOX..

Download Helper
http://www.downloadhelper.net/

Download MOST (99%) of the videos/flash on websites.
There may be better addons for youtube but as an overall addon for flash video this is better....

Tineye reverse image search engine

https://addons.mozilla.org/en-US/fir...il&version=1.1
Although lot more websites are to be added it is useful if you find an image and want to find similar images on net....

FACEBOOD FACEPAD

FacePAD (Facebook Photo Album Downloader) allows you to download entire Facebook albums with a click of a button, so you can access your favorite albums in offline.
— Download link : https://addons.mozilla.org/en-US/firefox/addon/photojacker/


FB CHAT HISTORY

Chat history manager Firefox extension which can save your Facebook chat messages in your browser, so You can view your chat history anytime either online or offline.
— Download link: https://addons.mozilla.org/en-US/firefox/addon/facebook-chat-history-manager/

 

Instant fox search engine
http://www.instantfox.net/ 

Makes all google, google image, youtube, wiki....... possible from addressbar within one go

.

Photo Zoom
A magnifier for facebook thumbnails (either profile pictures or album photos). When the mouse is over a thumbnail, a tooltip will appear with the bigger image in it.
 

Download link : https://addons.mozilla.org/en-US/firefox/addon/facebook-photozoom/