N00bs on Ubuntu shows you how to change the login screen on Ubuntu 11.04

Changing your login screen works the same as Ubuntu 10.10 maverick Meerkat. To enable the Appearance manager at login open a Terminal window (press Alt+F2 and type: gnome-terminal) and copy=paste the following line: sudo cp /usr/share/applications/gnome-appearance-properties.desktop /usr/share/gdm/autostart/LoginWindow Now close the Terminal window and logout, when logged out the

  Change Login Screen On Ubuntu 11.04 Natty Narwhal