You know that old sci-fi cliché of a sleek transparent glass pane becoming a TV / monitor when you turn it on? (Forgive me, I’m still watching Extant.) We already have transparent OLED displays, and of course the idea is ridiculously impractical for any real-life application. But what if you added a layer of smart glass behind the display, becoming opaque when you turn the picture on, for improved contrast? How cool would that look on your desk — or at your window?