Earth View is a very interesting program that uses photographs taken from orbiting satellites. It allows you to set your wallpaper or screensaver as an image of the Earth.

You can zoom in and out, set longitude and latitude and even use advanced options such as whether you want your photo to be taken during day or night.

What's more, a wide variety of extra maps and updates can be downloaded from the website.

The wonderful thing is that your screensaver and wallpaper get updated every few minutes to correspond with the rotation of the earth, so you'll never have the same one twice (well, not for 24 hours at least).