Review for Update Notifier by Draconis
Rated 5 out of 5 stars
This extension is so very useful that it should be standard in Firefox and Thunderbird. I no longer have to remember to check for updates to my numerous extensions.
I got it to work with Thunderbird 2.0 by using MR Tech Local Install and checking the "Override 'maxVersion' compatibility checking" box.
To create your own collections, you must have a Mozilla Add-ons account.