Rated 4 out of 5 stars

This is a great add-on. Truly indispensable for me. Unfortunately, it's not updated very often.
I can confirm that it's not fully functional on Firefox 3.6 (even forcing compatibility). The tab bar behaves strangely when I hover over it.
I hope Jomel can find the time to update it or Firefox 3.6 soon.

This review is for a previous version of the add-on (0.5.8).