what I hate the most with touch screens is that there is no feedback. on phones you can have sounds and/or haptic feedback (small vibration) but on a big screen like that i doubt the feedback would work.

So basically you 'press' a button (or rather tap a part of the screen) and you wont know that you pressed it until the action takes place. Unless you look at the screen itself to see the button_pressed state.. but how often do you look at your keyboard when you type?

That reminds me of an interesting article i read, from an ex-apple designer, regarding new technology ergonomics: http://worrydream.com/ABriefRantOnTh...ractionDesign/