Rated 5 out of 5 stars

This add-on is really a must-have when using vertical tabs. There seems to be a minor incompatibility with the Oxygen theme in FF4 though. I've filed an issue about it: https://github.com/piroor/unifiedsidebar/issues/2

This review is for a previous version of the add-on (0.1.2011021901.1-signed).