I own a wacom drawing tablet that has a pressure tip with multiple levels of sensitivity. The pen is not attached physically to the tablet, but as the pen moves close to the tablet, it creates a signal between the two and registers what buttons are pressed on the pen. I've looked around briefly to see how that works, but haven't found it yet. Also, my tablets pen either doesn't need power, or the energy cost to send those signals is low enough that the batteries never need to changed.

If there was a program running on the computer that could register buttons pushed on an IR pen, then the limit of only having one form of input could be overcome. It's annoying to only be able to move the cursor, or only click when using a program such as Autodesk's Sketchbook Pro where some features are built to support moving the cursor by hovering the pen above the tablet, then immediately tapping the tablet to activate a click. Also, adding a pressure sensitivity feature would be nice for drawing with different sensitivities.

Basically, if the pen could communicate with the computer digitally, then the only thing the camera would need to do is track it's physical location. All the clicking information could be sent through other methods.

I'm going to assume that the same technology used for the tablet pens connection would not be ideal, but then again either would hooking a bluetooth to your pen or something like that.

Really? That's great! Are they posting the information publicly or is it all internal. I'd love to follow it if it's public.