Xul: Creating toolbar buttons

Mozillazine has a great article on creating toolbar buttons. One thing they sort of go into is toolbar palettes -- here are the toolbar palettes I've run across:

MailToolbarPalette: the toolbar in Thunderbird's main window

MsgComposeToolbarPalette: the toolbar for a Thunderbird compose window

AddressBookToolbarPalette: the toolbar for the address book toolbar palette, but if you're trying to write an overlay for the address book, you'll need to modify your contents.rdf file to add an overlay for the address book .xul file.