CookieSwap enables you to easily swap all your cookies so that you can be logged in to multiple web e-mail accounts (like Gmail and Yahoo! mail) at the same time and quickly switch between them.
Adds a find bar button that allows you to search for a word or phrase on a web page and displays the results in an easy to view list. Also displays the total number of results found.
Case changer is a very handy addon that lets you change any selected text into lower case, Sentence case, Capitalise Each Word, UPPER CASE and tOGGLE cASE.
NoSquint is a Firefox extension that allows you to adjust the default text zoom level, which is very useful if you have a small display or run at a very high resolution. NoSquint also remembers the zoom level per site
This extension enhances the Full Screen mode into a really full screen mode, hiding the remaining toolbars and statusbar and making them visible again when the mouse pointer hits an edge of the screen.
A free Firefox add-on that lets you skip all the clicking and waiting on sites like RapidShare, Zshare, MegaUpload, and Sharebee. Your downloads start instantly.
Powerful and user-friendly selector utility for selecting elements and doing various actions on them. It can be used for cleaning up a page prior to printing it (by removing and isolating elements), and for web development