Walyk Wallpaper Changer
Bored with your computer's wallpaper? You could right-click the desktop, choose Properties, and navigate the Windows interface to redecorate--or you could right-click an icon and click "Next." Loading up Walyk Wallpaper Changer will let you do just that.
If want variety on a regular basis, you could also use this free tool to change the wallpaper at specific time intervals, every day, or every week. You can even add a calendar to your desktop.
Walyk Wallpaper Changer is initially challenging to set up. Load the program and you see nothing but a new icon in your system tray. You need to right-click that icon and choose Configure to get to the program's interface. However, once you get to the Configuration window, it's fairly straightforward to add images, set up your preferences, and so on. There's no Help option--but this program is easy enough to use without one.
If you frequently change your computer's wallpaper, this is a must-have tool.