Yes! Rated 4 out of 5 stars
This is just what I was looking for! Being an Opera user, I've been trying to recreate the same UI in Firefox. This pretty much finalized my search. But why did I only award it 9 out of 10? Because of minor cosmetic points: if the tabs are on the right side, the close buttons should be on the right, and the indents would look better if they'd be on the left. ;) Not a big deal...This review is for a previous version of the add-on (0.6.2008031101).