CNet has put together three volumes of the “best of Firefox” as far as extensions go. All three lists have useful extensions, some I have tackled and some I have yet to try. Here is more Firefox extension love than you can shake a stick at.
Check Out Volume 1
Check Out Volume 2
Check Out Volume 3
For those of you that don't know Mozilla Firefox is a fast, full-featured Web browser that makes browsing more efficient than ever before. Firefox includes pop-up blocking; a tab-browsing mode that lets you open several pages in a single window; integrated Google searching; simplified privacy controls that let you cover your tracks more effectively; a streamlined browser window that shows you more of the page than any other browser; and a number of additional features that work with you to help you get the most out of your time online.