OK. I blew away this post once already.. Let me try again.A Windows Screensaver is just an executable with a .scr extension. So, you can make any app a screen saver by changing it to an .scr file. If you put it in the Windows directory (or System... hmm.), it will show up in that list under display properties, and you can schedule it. You can't configure it yet, though... that takes one more step.
If you're writing your own app, all you have to do is take a '/s' command line argument. When you get that, bring up a properties dialog that does all of your settings (usually using registry settings). When you hit the configure button (or whatever it's called), it starts the app up with a /s cmdline arg.
That's all there is to screensavers. I don't know if anybody asked for this, but this is something i stumbled upon a time back. It works with any app... even things like Word or Explorer.exe.