Rated 5 out of 5 stars

Just wanted to say that this addons does work with Firefox 4 Beta (Using it with Firefox 4 Beta 8 at the moment) Just install it after installing something like Add-on Compatibility Reporter:
https://addons.mozilla.org/en-US/firefox/addon/15003/
And you'll be able to install regardless of what version of FF you're using.

This review is for a previous version of the add-on (1.0.1.1-signed.1-signed).