Rated 5 out of 5 stars
This extension simply works, and works perfectly. The ultimate solution for having a quick backup to rely on if something goes wrong adding comments around the net.
In fact, I actually used the functionality of this add-on posting this very comment. Upon hitting "submit review" I got a 403 error from Mozilla's site losing my original comment, though Textarea Cache had my comment ready and waiting to be copied back. :)