Desktop Earth is an interesting desktop wallpaper generator Windows.
Every time you log on Desktop Earth gets updated picture of the Earth made from satellite and loads as wallpaper. Pictures are formed at high resolutions (2560x1280, even), so there should be no problem in fitting them to the screen.
Very relaxing screensaver with the sound of flowing river. With it moving to Oak Creek Canyon and Sedona Arizona - a place known for its beautiful scenery. Red rocks and flowing water create a peaceful and relaxing atmosphere.