Review for MinimizeToTray by Fentzy
Rated 5 out of 5 stars
I hacked it myself to work for Firefox 3.0 with the information here (thanks everyone!). I figured I'd save everyone else the trouble by uploading my hacked working version to a free file server for others to download.
Get it at:
http://www.savefile.com/files/1618642
To create your own collections, you must have a Mozilla Add-ons account.