Although Windows is getting better at making the desktop more usable and more interesting as a background to your work, it can get a bit dull watching the same picture all the time.

Install DeskDeco and you can have a new desktop image every day. It will automatically start every time Windows starts, and will add an icon to the system tray, through which you can access the program controls.

It only has a few options, making it simple to use - just choose a folder containing the pictures you want the program to cycle through, tell it how they should be displayed and for how long, and you're in business.