Ok, if you guys can stand yet another slight modification to this wonderful theme (which I take absolutely no credit for save for my own slight modification.)
This is a Mac OS X type Login screen, but beautified to depict Debian Linux, and more specifically, SimplyMEPIS - my favorite variant of Debian.
I highly suggest the use of the KDM Theme manager to install this theme. I have no idea how to modify the config files manually to enable it. Good luck and enjoy!