HID Compliant TouchScreen for OS X 10.6
Google found a couple of possibilities; I haven't tried them myself:


NextWindow - Touchscreen 2700
Planar Touch - Touchscreen LCD Monitor - PT1710mx 17" Monitor


There's the Wacom Cintiq; while I believe they need drivers I'm sure they'd be available close to day &amp; date.

And an entirely different approach to take might be the Axiotron Modbook.