I have long thought about human interface device since I was mentored by Dr. Peng Guo. It is about the year 2004 when Dr. Peng Guo was interesting on embeded multimedia system. Since touch screen is a tiny component of the whole ARM-based system, I never had time to investigated on the driver development of the touch screen.

But I have a good thought of a gesture-driven touch screen:

- A list of menu will be shown when multiple-candidate operation is available. The order of the items in the menu is dynamic and sorted according to the probability of their likely-click hood. The most likely one will be located at the top of the menu. And it is context-aware.

- More than just simple click, moving and drawing are applicable to HID. Though they will be the most common gesture, man should have some others which are more convenient ones and can substitute the combination of these simple gestures, such as drawing a cross or a right mark, round a circle. 

- Current factors considered in the touch pad includes only the position of the point and click. But usually people express their thought in many other key factors, e.g. acceleration, closure of the trace, etc.

However, maybe all these thinkings were already late in 2004, since Synaptics was existing that time. And it is too late now since Microsoft has published its multi-pointing HID design and Apple's iPhone is already on sell.