BackgroundFader is a very unique Windows application that fades through background images on your desktop at regular intervals. To set up BackgroundFader, just pick a folder that you want the program to search for images in, set the interval (in seconds) at which BackgroundFader should change the background, and you're ready to impress. You can also make the application run when your computer starts up, just check the box.

BackgroundFader is located on this website, in the Free Stuff area.