This extension will enable you to organize your status bar icons. You can now rearrange or remove any item (icon or text) in the Firefox status bar. If your status bar is full and cluttered like mine was, give this a try.
Allows you to keep separate keyboard layout for each tab and url bar
Keep track of and show your friends what music you listen to from YouTube, Pandora.com, Grooveshark.com, Meemix.com, and more, in real time, and even show it directly in Facebook.
Add useful extra features to Google Reader, like feed favicons, inline article previews, and unread counts in your browser tab with Better GReader.
Change your bookmark icons! Right-click a bookmark, and select "Properties", then "Browse" for a new image or paste in a URL.
Adds the possibility to open non-linked (plain text) URLs in new tabs or windows.
An extension to hide the caption of Firefox, displays Minimize, Maximize/Restore and Close buttons on the menubar/nav-bar, and includes "Tiny Menu" function. This extension also provides "Bookmarks" and "Histroys" buttons with popup menu.
Note from Mozilla: This add-on has been discontinued. Try Evernote instead.
Clipmarks lets you clip and share specific parts of articles, or anything else you read.
Platypus is a Firefox extension which lets you modify a Web page from your browser -- "What You See Is What You Get" -- and then save those changes as a Greasemonkey script so that they'll be repeated the next time you visit the page.
Makes unused tabs fade with age and highlights the selected tab...
Tabs Open Relative makes all new tabs open to the right of the current tab, rather than at the far right of the tab bar (optionally this only applies to links).
Collections are groups of related add-ons that anyone can create and share.Explore Collections