EarthDesk is a very nice application that changes your desktop picture to an awesome picture of the earth, with updates every couple of minutes. If you are bored of your old desktop, why not have a real time earth as background! This application works for both windows and macs. Earthdesk has real-time clouds, accurate sun and city lighting, centering around one city, multiple display support, and many more features! One of the best features is probably the city lights during the night.

I have been using the evaluation copy for some time now and I really like the application. My favorite features is when you see all the city lights during the night. It is unbelievable how lighted some cities are. It is also really cool to see the current cloud patterns everywhere around the globe. All in all, I think this is an amazing application and a must have for your desktop!
Here are some pictures of it in action: