rebhana: Maemo doesn't seem to use /etc/gnome/defaults.list and I want to be able to port this back to the old N8x0 tablets...

Also, /usr/bin/dbus-switchboard-shim looks like it is supposed to do what you're looking for with the osso PDF reader...

ruskie: I have figured out how to get mailto: working. Just add it to the .desktop file along with the other protocols. Next version will have all the protocols listed...