Lifehacker wrote an article on their favorite experimental Firefox extensions today. Great article, and worth a read.
See also:
Lifehacker’s Favorite Experimental Add-ons
Mike Morgan 
About the Author
Mike Morgan is the Director of Web Development for the Mozilla Corporation. Mike joined the Mozilla community as a volunteer in 2003 and has worked on Mozilla's mirror management software, update system and addons.mozilla.org. These days he spends most of his time on strategy, recruiting and helping his team embrace their inner nerd.
