PC mouse input - absolute positioning?

[evandude]

I just did some reasearch on how resistive touchscreens work, and when I realized it's as simple as driving 5v and ground to a couple pins, and measuring an analog voltage on another, I started looking for cheap ones.

Turns out the Palm PDA digitizers are extremely cheap on ebay (around 4-5 dollars apiece, if not less) and utilize the easy 4-wire interface.

I have several uses in mind for various projects, mostly microcontroller things (for example print off a button layout, stick it behind the panel, and you instantly have a custom panel of buttons that looks nice)

However, I am also interested in some PC-related things, and to do some of them I would need to be able to communicate an ABSOLUTE mouse cursor position to the computer (like a graphics tablet would) as opposed to a relative movement (like all standard computer mice/trackballs/touchpads do).

Does anyone know of any software that does this? my quick google searches didn't turn up much. Ideally it should be PS/2 or serial interface, as USB is too complicated and expensive for my taste, and not all the computers I have in mind have parallel ports.

thanks