I have a computer whose display I want active all the time, but that I don't want people coming up to and doing anything on. At the same time, I want the keyboard and mouse to remain connected because even though they will seldom be needed, when they are needed it's important that they be available quickly.

I guess I'm looking for a screensaver that doesn't save the screen. Something that prevents the mouse and keyboard from doing anything unless a PAM authentication is entered, just like a screensaver would.

Does such a piece of software exist?

Thanks.

Im not sure if this would do what you're asking.. But check out unclutter