Smart Bookmarks Bar
Takes away of your bookmarks names in your bookmarks toolbar. So basically, you can add more bookmarks in your bar, because it doesnt take up as much room. Doesnt work with all themes, so i suggest to use...
You can pick from many different, and good, themes for firefox. It also works with the Smart bookmarks Bar!
A tip I picked up from LifeHacker is to use these two add-ons together:
This is an experimental add-on (in other words, it's not a stable release), but I have had no problems with it thus far. It allows you to keep tabs you choose in a permanent spot-- you can move them around, but you are unable to close them by accident or by the "close all tabs" options. You can't close them at all unless you disable them as permatabs.
Combine that with the faviconize add-on to create small, permanent tabs on one side of your tab bar, so you don't have to open them manually and you don't have to worry about accidentally closing them. They'll be right where they were before every time you start up Firefox. Good for something like an email page or forum site (for instance, ZU is one of my permatabs).
It is useful when bidding on eBay. You can highlight text on eBay when bidding on something, and it will refresh the page every 5 seconds, 1 minute, 5 minutes, or every hour by default (this is customizable to your liking). If it finds that the text you highlighted has changed, it will notify you by flashing the tab (in Firefox and on the taskbar) and making a (rather loud) sound. This is useful for checking the price every once in a while without having to refresh it yourself and sit on the page for how ever long the bid has left.
"In a mad world, only the mad are truly sane."
"If an A is a success in life, then A=x+y+z. X is work, Y is play, and Z is keeping your mouth shut." -Albert Einstein
Fire.fm Note: To those who live outside the US, UK, or Germany Last.fm is not free. The price is either $3 or €3 a month.
This is a must have for anyone who frequents Last.fm. It adds a toolbar that gives you access to last.fm's music library, allowing you to listen to music while browsing the internet. Very simple to use, but if you don't know how to get it working simply click on the flashing orange radio signal. If you're one of those minimalists who worries about loosing too much space to oversized toolbars and junk like that, this is about how large it is.
(Word of warning, this add-on can cause Youtube videos to glitch or act weird, this is usually resolved by refreshing the page)
Adds 3D tabs to your browser. At first this doesn't seem all that useful, but if you also use Tree Style Tabs and hate constantly opening and closing the tab bar, then this is a life saver.
FoxyTunes: Let's you listen to music through FireFox. The application you are using must be open, but you can press play, pause, and fast forward from a little toolbar. It supports WMP and Foobar2000, but you can also do Last.fm and Youtube from it.
Yoono: Let's you chat on IM and check your Facebook from a sidebar.
Aniweather-Allows you to see the weather on the bottom of your browser, also allows viewing of weather alerts. Useful if the weather currently isn't on TV, or you're on a plane and want to know what it's like where you're going