This doesn't seem to do anything with Firefox 11 on Mac OS X (10.6.8).
The preferences are not very useful, either. A ctrl-click and a right click (usually a two-finger click on the trackpad) are usually the same thing and they open the contextual menu for the toolbars, which is where one can hide the toolbars or edit the icons on them.
Single click isn't great, because one might not want to stop all the tabs with a single click.
So I chose double-click, but it doesn't appear to do anything.
I'd like to see support for shift-click, or opt/alt-click.