It may not be as popular as Google, but Bing does have some amazing background images that many people would like to use as wallpaper. If you're among them, ZapBing is the tool you're looking for.
ZapBing downloads the background images used in all versions of Bing (American, German, French, Australian and Japanese) and can be set to display them automatically as wallpapers on your system. Downloaded images don't have a very high resolution (they're 958x512) and won't fit largest monitors, but they are still usable.
The best about ZapBing is that it can display those images with a variety of effects. Besides the usual full-screen and centered modes, the program includes a Polaroid mode and a Photo stack mode, which make the images more attractive as wallpapers – and also enables you to use them on larger monitors.
Like other wallpaper managers, ZapBing can be scheduled to rotate wallpapers according to a certain time frame, though you can also renew it manually at any time by double clicking the program's System Tray icon.
Even if you don't use Bing as search engine, you can enjoy its beautiful background images as desktop wallpapers.