EarthDesk is a program that puts a map of the world on your Windows or Mac PC's desktop. It includes a number of rendering options, such as optional true cloud coverage downloads (at configurable transparency levels) and configurable moonlight for nighttime areas. You can also choose between different map projections, everything from a true round globe to a rectangular map.

EarthDesk is unique in that it is available for both Windows PCs and Macs - too bad more software vendors don't go this route. There is an evaluation version, but it puts a huge ugly watermark in the middle of the map that may make you want to vomit - okay, that's a bit harsh, but then so is the watermark. A single user license costs $19.95, though it seems more people would pony up if they could actually try the application without the watermark for a period of time.

For a free Windows alternative, check out Desktop Earth. If you know of a free Mac alternative, let us know in the comments.