Now, I'm familiar with elotouch from my POS days, and they were the first place I looked. They do have mac drivers, but there are a lot of footnotes next to the driver:
Elo TouchSystems Multi-Touch Add-on 4.1.10
(1.3 MB) Mac OSX 10.7 Lion USB, Serial
All except APR,
Projected Capacitive and optical
That's a whole lot of technologies that aren't supported! I'd like to find someone with an elo monitor to test it for me before I drop the cash.