So I kinda lied, I do run this on my machines:
http://www.xericdesign.com/earthdesk.php
Every computer i've ever owned, including my palm pilots, phones, ipads, desktops, has had some app that can show me a sunlit earth. So this is what I currently use.
I actually subscribe to their high res cloud service, which looks gorgeous.
So I have a live wallpaper, but that's about it.