I have started development on a revolutionary way to control an iPhone and an iPod Touch. It takes advantage of two key developments:
1. No spinning media in the iPhone or iPod Touch
2. An accelerometer is built into both devices. The accelerometer allows the devices to change between portrait and landscape depending on how the device is being held, upright or on the side.
The problem being solved is that to control play, volume, and track you have to look at the iPhone and iPod Touch; with a click wheel you could keep your device in the pocket of your hoodie and make any changes by feel. Using a good flick of the wrist we will be able to control playback of the devices.
To go to the next track, flick the top of the device to the right
To go the previous track, flick the top of the device to the left
To up the volume, flick the bottom of the device to the right
To decrease the volume, flick the bottom of the device to the left

To play and pause the device you would flick the top of the device up

Once I have the basic operation working, I will allow users to build macros; i.e. left-right-up-down will unlock & play the Celine Dion you have hidden on your device.
I really think this will make the devices a lot more useful, without the tactile feedback of the click wheel the iPhone and iPod Touch are a lot less user friendly.
-Matt