It's probably not the height of efficiency, but Crystal Wallpaper is certainly original. The utility is a desktop image manager, helping to switch background pictures manually or automatically. However, it also gives users the curious ability to display those images on top of all other active windows, in a translucent layer, instead of behind them. Users can increase or decrease the layer's opacity, change images, or disable the utility all by using keyboard shortcuts, but the program does takes a fairly hefty bite out of system memory while running.
If you're intrigued by the idea of seeing a picture of your dog or child superimposed on your Excel spreadsheet, then this download may well give you a kick.