xscreensaver has some minor issues under OS X. (Desktop-morphing hacks can't grab the desktop because Apple's X server doesn't implement what would be some rather complicated Quartz -> X business; X apps aren't allowed to take over the display so the dock still runs and makes it useless as a screenlocker. I only know this because I was bored and flipping through the documentation... Ironically, being able to have a (secondary, screenlocker-specific) dock on top of the locker is Something I Would Dearly Like to Have, since my box has an internal speaker with no physical volume control and I tend to walk away and have it autolock with music blaring. Being able to put a 'secure' volume control and stuff like note-leaving apps 'on top' of the screenlocker would be rather cool.)

Okay, uh, as to the importance of screen-savers; they get more important as screens *don't* need saving. It's not about shit happening while you're not there (something Pointcast etc. never learned), it's about shit being there when you get back. The iOpener actually did this smartly; leave the display on at little power wastage, and you've got the time, weather, number of mails waiting staring you in the face when you come back. (More generally, a clock always comes in handy.) It's not about 'push,' it's about prediction.

As to screen hacks that take advantage of the network in one way or another, there's always that Electric Sheep thing, and http://www.daliworld.net/index.html || http://www.dalilab.com/ is something of a cute idea. (Also amusing as an instance of a 3D app written in Java, and it really isn't all that slow for it.) Flying toasters were pretty gimpy if you'd ever seen a real 'demo,' but yeah, we know, anything you could do easily on an Amiga doesn't count until it's copied with much pain and effort on [Win|Mac|*NIX].

Until I get a big efficient burn-in-free flat-panel that can automatically pop up a live HD feed of [insert interesting webcam locale here] and overlay it with the current time, my inbox-status, stock ticks, load average, countdown to next PIM alarm type-event and so on, I'm sticking with DPMS.

Also why did the X (windowing system, not Mac) protocol have to break such that xmove doesn't particularly work with anything cool such that implementing the equivalent of 'fast user switching' becomes a giant pain in the ass rather a simple and elegant demonstration of why the client/server abstraction is Good?