I just started working on pretty much the exact same thing. My dad is a quadriplegic and I was hoping to use a mouth switch (
http://conceptusinc.com/tongueswitch.htm) to activate the next/previous page buttons either directly (soldering the switch in parallel on the motherboard) or through a microcontroller. A micro would be able to interpret long or short presses, or even different predetermined sequences of presses, and then activate different buttons. Using the serial port would be ideal if I could issue commands that would mimic any of the buttons, and it would save I/O pins and a lot of soldering. Can anyone provide a list of commands that would activate different buttons? I will be getting the DX tomorrow so I will start playing around with it connected to a pc first, so I'll follow up if I find anything out. I haven't found this information anywhere online yet, so I thought I would post here in the meantime.
Thanks!