How do yo handle the practial installation (installing when users potentially logged on)?

I have not made up my mind yet how to handle deployment of certain applications.
That is the main reason why I dont use schedules much.

Because, regardless of time of day, users could be logged on to the computer.

To counter this I have used a script that warns the user of the deplyment and gives him xx minutes to save his work before the intallation starts.
He can also opt to cancel the install.

Often a deployment has an affect on a runnin gprogram. (Java kills browser, other installatins might even requere an reboot)
I would have a lynch mob in my office I went ahead and deployed applications like that, without any "heads up".

This is even more important now with the release of v 3.2 with auto deployment.

So how do you handle this?

My hope:
What I really miss is a "Warning optoin" in the package properties.
For autodeployments, this should be set on the autodeployment schedule itself, so it was kept for all future packages linked to it.