A slew of new Apple patent applications have come to light covering a rather odd range of functionality that may -- or may not -- make it into future iPhone software and hardware models.

First up is haptic feedback via a "grid of piezoelectronic actuators", which would provide a varied tactile response when touching the iPhone screen to better orient users (and let them type without locking their eyes on the keyboard, ideally).

Second is a technology that seeks to identify fingerprints -- i.e. not only that a user has touched the screen, but which specific finger touched the screen. So, for example, touching with the index finger would produce a different reaction than touching with the middle finger.

Third is for placing a RFID (radio frequency identification) reader in the screen so that, in addition to finger touches (and multi-touches), it could identify the unique tag given to objects as well.

Lastly is a method for letting users sing to the iPhone, and having the iPhone provide feedback on tone, pitch, etc. Basically, rating the quality of your karaoke -- or of the latest pre-packaged Hollywood auto-tune single, we imagine.

Again, there's no telling when, or if at all, Apple will release real-world products based on these patents, but they do give some hint as to which direction(s) Apple's thinking.

Anyone want any of the them now?