EarthDesk replaces your desktop picture with a high-resolution image of Earth, complete with accurate current lighting conditions (sun, moon, city lights, and real-time clouds). This image will change throughout the day to reflect the movement of the sun, moon, and clouds in real time. Tons of features like city lights at night, zoom capabilities, and political and satellite maps make this a top-notch earth viewer.
What's new in this version:
Changes to support single or "all spaces" under Lion (OS X 10.7).