Does this utility exist? If not, could it in theory?

[ToastyX]

I don't think a utility like that exists. Windows doesn't provide a mechanism to control the screen like that. I can only think of two possibilities. It might be possible by hooking into the desktop window manager, which would involve extreme hackery and is something I'm not familiar with, or it might be possible by creating toolbars similar to the taskbar to control the position of the desktop.