Rated 4 out of 5 stars

Please add Google Buzz.
4 starts because it should load the services remotely so it wouldn't get out of date.

To add GoogleBuzz manually:
1. Open USER\AppData\Roaming\Mozilla\Firefox\Profiles\YOURPROFILE\extensions\{3e0e7d2a-070f-4a47-b019-91fe5385ba79}\
2. Rename addthis.jar to addthis.zip
3. Unzip all
4. Download GBuzz image http://img6.imageshack.us/img6/7551/googlebuzz.gif
5. Open the folder chrome\skin\services\ and paste the image there
6. Open chrome\content\Constants.js
7. Add this line above GMail line
> "googlebuzz":{"title":"googlebuzz","cat":"BLOG"},
8. There you go.

This review is for a previous version of the add-on (3.0.1).