Alright, I said I would talk about MinimizetoTray so here it is. At work, I always have to have Thunderbird and Firefox open. It was taking up some valuable taskbar space, so I went hunting for a way to minimize things to the lower-right "tray".
Firefox1. Click on the green "Install Now" and follow the instructions.
2. Restart Firefox as it prompts.
3. Go to "Tools > Add-ons > MinimizeToTray > Options" to minimize to tray automatically.
Thunderbird1. It is the SAME LINK as before, except you need to right-click and "Save As..." the file to your computer.
2. Also
download this .xpi file.
3. Open Thunderbird and go to "Tools > Add-ons > Install". Find the .xpi file you saved. First do the MinimizeToTray, restart Thunderbird, and repeat steps for MinimizeToTray Enhancer.
4. Go to "Tools > Add-ons > MinimizeToTray OR MinimizeToTray Enhancer > Options" to set preferences.
And as a bonus, I'll tell you how to minimize iTunes to your taskbar! (Note: I am using an older version, but instructions should still be the same.)
1. Load iTunes.
2. Go to "Edit > Preferences" (or hit Ctrl+,)
3. Go to the "Advanced" tab.
4. At the bottom, check both "Show iTunes icon in system tray" and "Minimize iTunes window to system tray".
Enjoy!
PS: Don't forget to close out of these windows! Having them run in the background does take up a load of memory if you are trying to do other things (ie: watch videos or play games).