MacRumors unearthed two patent applications filed by Apple in the past couple of weeks that indicate the company is researching motion-aware interfaces for the iPhone.
It works like this, the iPhone would be able to detect when you’re moving (via GPS or the built-in accelerometers) and adapt the interface accordingly. If implemented, your iPhone would know when you’re in motion and could enlarge the size of on-screen controls so that they’re easier to see and to tap. More at; http://blogs.zdnet.com/Apple/?p=3703