If you have many beautiful background pictures and want to change them frequently, but the manual effort is quite too much to worth, then try the handy JDWall freeware tool.

JDWall lets you create a list of JPEGs or BMPs that you like and automatically changes the wallpaper using these images.

You may get a new wallpaper with each system starts or set the duration when you want the program to automatically set up a new background!...Read more about JDWall