Re: Changing Wallpaper can have career enhancing effects
"a lot of confusion when the mouse is going the wrong way"
Nice one. I've done the screen grab, and hide all the icons and task bar - never thought about the rotation though.
Another option would be to use a suitably sized screen grab from an entirely different operating system. For completely pointless reasons, I did that to my own machine at one point. (I didn't hide the taskbar because I wasn't playing a prank, and I don't generally have many icons on the desktop.)