People interested in tangible/gestural interfaces and mobile devices may be intrigued by this patent filed by Apple. Called "Techniques for interactive input to portable electronic devices", the patent is about:
"A game input area (surface or plane) receives input for multiple applications including an interactive application executed in connection with a scene. The input received is directed to the appropriate application based on one or more locations (e.g., points, positions, regions, portions) of the input area effectively identified when input is received (or entered). In addition, the manner in which input is received (or entered) can be used to determine which application should receive the input. The input area can additionally resemble or approximate the shape of a scene (e.g., game scene) to allow a person to provide input in a more intuitive way. Accordingly, input can be provided in a simple and more intuitive manner by effectively allowing the user to interact with the input area in a way that mimics or approximates a desired action (e.g., moving a ball or bat around by inputting a rotational movement). Examples of such interaction include positional, directional (e.g., rotational), press or pressure input (or movement) which can easily be provided by a thumb or a finger, for example, on a touch screen. (end of abstract)"
That website gives more concrete details with some pics that are more explicit about "Examples of such interactions include that can be characterized as positional, directional, rotational, pressing and/or pushing type inputs (or movement)":
Why do I blog this? the idea of the patent is to have "multitasking" input techniques that would enable iPod/iPhone users to play games on the touch-screen while at the same time maintaining control of a secondary application from the screen. I take it as an interesting signal of upcoming applications on the iPhone; of course it's not the "iphone" word that is important here but instead that there is some good potential to see entertainment innovations with such interface due to a combination of factor: flat-fee internet subscription, touchscreen, easiness to develop web-apps, etc.