If an agent, replication, or save action from another user changes the back-end document, then show this in the front-end UI document.
This Idea comes from a comment from Bruce Lill in idea "Problems of conflict situations".
Bruce, I like it so much that I made this idea out of it. Credits to you!
IBM could actually add this functionality to XPages as well. Use Ajax to update the controls when the documents on the server changes.