"Touching a screen all day sounds terrible to me. I'm a trackball and trackpoint guy so my mouse hand stays stationary all day (except typing of course)...and I wouldn't have it any other way. Ergonomics are far more important than looking cool.
A good trackball is far, FAR more accurate that touching a screen anyway so the accuracy argument is garbage. Even a cheap standard mouse is better....
I really detest finger prints and finger smudges on my screen anyway. Maybe I just have especially greasy fingers but I wouldn't want to clean my screen twice a day.
Also, what about modifier keys (ie ctrl+click etc.) or even double click vs single click? I wouldn't want to need to learn some 'secret tap' sequence to do something that a mouse can do better, faster and smarter (or keyboard for that matter).
Maybe when voice recognition gets better and we can eliminate the keyboard altogether. Why would we want THREE input devices (keyboard, mouse and multitouch)?" (Continued via OSNews, kenji) [Ergonomics Resources]