Comment 58 for bug 445123

@jgoddard
          To disable face browser login run the following command:

sudo gconftool-2 --direct --config-source xml:readwrite:/etc/gconf/gconf.xml.mandatory --type boolean --set /apps/gdm/simple-greeter/disable_user_list true

         This will then only give you prompts for username & password. This isn't a workarond. It just is not exposed in login UI.