Here's one from left field: you know how your car's navigation console locks itself when in motion, whether or not there's a passenger to safely operate it? Apple, of all people, wants to fix that.
In a patent filing recently published and dug up by Apple Insider, Apple lays out various methods, including weight, proximity and biometric sensors, for detecting a passenger in the front seat, and then allowing he or she to operate the nav while the car is in motion. It goes even further, though, by specifying means for the system to identify exactly who is touching it via biometric sensors, and then grant them access or not depending on pre-set safety settings. So if you don't want your 16 year old kid using the nav at all while in motion, just thumbprint him and program your Apple GPS.
Wait, what, Apple GPS? While apple has patented numerous techniques for pairing gadgets to cars, I'm not sure I've ever seen one that was so specifically geared toward an in-car device. Innnnteresting. Although this could obviously describe a way for a turn-by-turn iPhone 3.0 app to behave in-car.