I just upgraded to Ubuntu 11.10 and I was wondering if it's possible to show a login banner with text... my company's IT policy requires that some generic text be shown at login. I've seen where you can change the background, so I guess I could make a background with the text in it, but I wanted to see if there is another way.
In Ubuntu 11.04, I was able to do this with the following commands...
sudo -u gdm gconftool-2 --type string --set /apps/gdm/simple-greeter/banner_message_text "`cat issue.txt`"
sudo -u gdm gconftool-2 --type string --set /apps/gdm/simple-greeter/banner_message_text_nochooser "`cat issue.txt`"
sudo -u gdm gconftool-2 --type boolean --set /apps/gdm/simple-greeter/banner_message_enable true
Answers provided to Hamish Downer's question about LightDM themes linked in the comment to my original question include a suitable answer to this question as well.