Another patent focuses on facial recognition, which can also be used for a variety of purposes. It could bring you info about a person (scary, I know) just by pointing a camera at him; or it could be used for security, enabling only recognized users to use the device (even scarier; imagine your iPhone refusing to work after you've had a shave and a haircut). Whatever the implications, I'm really excited about these technologies, which would take the iPhone (and similar devices) to a completely different level.
Finally, Apple filed for patents for better voicemail management, changing the voice output, or filter obscene content from text messages. There's an exciting future ahead; I just hope we won't have to wait for another generation of iPhones to see these in practice. Check out Apple's patent applications here.