Rated 5 out of 5 stars

From the author:
"I'll definitely be updating the extension for use with FF3 (and others) including update notifications for the browser itself. I'm sorry for the lack of updates but I've been quite consumed with working on the Gmail Manager extension which I'm thankfully close to releasing (for use with FF3). As soon as I get a release out for Gmail Manager I'll begin my development shift towards Update Notifier."

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