Lifehack.org has published a list of their essential firefox extensions. Some of my favorites are naturally missing, but that’s okay with me-there are a lot of excellent suggestions here, and there are links under the list to favorite extension lists around the web. I really like this list; there are a few here that I have and a few here I’m dying to try. You might want to give it a whirl; you might find an extension you never knew you needed!
[ http://www.lifehack.org/articles/lifehack/essential-list-and-resources-on-firefox-extensions.html ]