Going dual-screen is really the nuclear option for smartphone design -- it's what you use to draw attention when your regular, single-screen phones aren't thriving. We're at once unsurprised and appreciative, then, that BlackBerry has applied for a patent on a dual-screen phone concept that hasn't gone further than a filing. As shown, it would embrace the familiar concept of running separate apps on each screen, with a slight twist: it could recognize touch gestures that span both displays, such as a pinch to switch app positions. Naturally, it could recognize distinct gestures on only one side or put a keyboard on one display for typing on the other. Given BlackBerry's current design directions and very different gesture concepts, the application is more of a what-might-have-been than any kind of roadmap. It's just as well when many twin-screen smartphones haven't exactly panned out.