Yesterday the US Patent Office published an application for Apple's next generation screens. The coolest new feature: a recently developed Privacy function. It would only allow someone viewing the screen head-on to read what's on it.
It's controlled by something called a Beam Steering Module, which refracts light off the screen in such a way that it's visible only within a narrow angle of space. If the technology ever does make it onto the production lines, Apple wants to see it everywhere private viewing is desired — from ipods to medical equipment to vehicle instrument clusters.[Patently Apple]