I have set a policy in Active Desktop to display a message on the curriculum computer wallpaper. The current one is asking them not to push the monitor right down when they have finished. It's certainly a good way of getting the message across. It would be nice to be able to display more than one message. I've seen software that allows wallpaper to cycle but is there anything that could be controlled by the group policy setting on Server 2003, so instead of displaying the designated image file, it produces a slideshow?
How about a logon script that copies the desktop image from a server to a known location on the workstation (set this in GPO).
Then have a rotor script runing on the server to change the messages.
That way you will change the desktop as they log on, and in a computer room will probably end up with most of the messages...
The other way (which I haven`t tried) would be a active desktop background, with a refreshing webpage?
You should be able to use BGInfo to display several custom messages on their desktops at once.