For those getting bored with GDM 2.28 default greeter.
This is GDM 2.28's default greeter UI modified for a horizontal arrangement.
You need to copy the downloaded file to
(back up the original first!)
I removed some bits of the original login screen because I don't use them:
* User list container
* Custom message field
You must turn off the user list for this to work! See : http://ubuntuforums.org/showpost.php?p=8100229&postcount=8
You can run
[indent]sudo -u gdm dbus-launch gconf-editor[/indent]
from your session to access the GConf settings for the login screen.
Tested on 10.04 and 10.10 working.
Don't forget to vote! ;)