MacRumors found three interesting patents that point to various new interaction techniques. The most interesting is the fingerprint ID directly on the screen so that the iPhone can see which finger you're using and accept gestures appropriately.
The fingerprint ID also, of course, can theoretically act as a security device so that only you can activate your phone. There's also haptic (physical) feedback when you're hitting things, as well as using the touchscreen as an RFID reader. None of the three are really mindblowing in themselves, on the surface, but if implemented intelligently might make for a big step forward in the iPhone product line. [Macrumors via Boy Genius]