Rated 4 out of 5 stars

doesn't work, completely with Nightly 22, BUT... disable all but location bar and in conjunction with HideBookmarksBar by Felix Kloft and it Rocks.
Ctrl+Alt+B bookmarks, Crtl+Alt+N navigation bar and i have a big development space..
oh, you have to decompress and edit the install.rdf to change the MaxVersion number as this apparently has not been updated since ver. 3.x ..