This is basically telling you to let somebody else run xplanet for you, then download the results every four hours. Pining for my xearth root window of yore, I wrote up how to run xplanet on your local machine, rendering out a nice new version every few seconds. This makes your desktop a useful global clock.
those clouds are real[1]. So it can be used to predict weather :)
> Watch the sun rise and set all over the world on this real-time, computer-generated illustration of the earth's patterns of sunlight and darkness. The clouds are updated every 3 hours with current weather satellite imagery.
Also it's possible to do this automatically in Windows 7 if there is some sort of RSS[2]
I tried that in Windows when they first implemented it, but didn't find it very useful. I'm one of those that actually use my Desktop for stuff I want quick access to (docs to read when I have time, docs I'm working on, etc.). Having the icons obscure parts of the webpage just didn't work all that well.
http://www.njl.us/rotating-picture-of-the-earth-as-ubuntu-wa...