GDM2 Setup is a GUI configuration tool for the new GDM (2) something that was missed by a lot of people. It doesn't have as many options as the old GDM setup tool, but that's because the new GDM2 doesn't support too many customizations.
GDM2 Setup finally got a nice GUI:
And a PPA you can add using the following command:
Then, to install it:
Once installed, you will find GDM2 Setup under System > Administration > Login Screen (GDM2Setup)
If you encounter any bugs or want to request a new feature, see GDM2Setup thread @ ubuntuforums.org
sudo add-apt-repository ppa:gdm2setup/gdm2setup
Then, to install it:
sudo apt-get update && sudo apt-get install python-gdm2setup
Once installed, you will find GDM2 Setup under System > Administration > Login Screen (GDM2Setup)
If you encounter any bugs or want to request a new feature, see GDM2Setup thread @ ubuntuforums.org