Maybe that would be cool... But how about the overhead of having to maintain that encrypted database.. Or would this be something that the users would be given a tool to customize/add things to themselves?

I think I would turn this feature off, simply because the pop-ups would likely get in the way of me using the player to, like, play MP3's. I love the fortune cookie type thing a la UNIX as you've described, but those didn't "pop up," they were just displayed during login and didn't get in the way of anything.

But as you've said, no RAM cost or anything, so go ahead... Just give us an option to enable/disable it?

Really though I'm just nay-saying here because I'd rather see you work on userland app-interface type things like that disk-writing idea.