How would you expect to use Photoshop with a touch screen, exactly?
Photohop seems all about precision, and not to mention has pretty tiny UI elements. Seems to me your finger would just get in the way more than anything else.
Pros use stylus type interfaces (e.g., a Wacom Cintiq) for the precision and not having one's own hand get in the way of seeing what one is doing.
Plesae understand, I'm not being critical of your request. As a non-touch user myself I'd just like to know more of what you're thinking.
for eg the sony duo (and I assume Flip but not checked it out) uses a pressure sensitive stylus which works with some software but not PS - as far as I understand there has been a standoff between adobe and someone in MS, but lets face it Adobe will loose csutomers not MS....for pcs at least. So I am wondering if MS laptops don't support adobe/adobe don't write for MS pcs, do anyother pressure sensitive stylus-touchscreens computers support PS (or adobe support them?)