Rated 3 out of 5 stars

16 Feb 09: 1.19 could not be installed ... not compatible with Thunderbird 2.0.0.19... only versions 2.0a1 to 2.0b1
17 Feb 09: add this temporarily to your TB options: boolean, extensions.checkCompatability -> false and you can Brit to your hearts content.

This review is for a previous version of the add-on (1.19).