Do you want to touch the screen?
mullr: A touchscreen doesn't replace a mouse - as you've noted it's not precise enough.  It can work with a UI that's designed for it specifically.  But you give up a lot of screen real estate to make that work.  (I've spent the last 3 years working on a touch-screen kiosk app...)What's really interesting is the multitouch stuff, especially with very large displays.  Once large, very high resolution displays become affordable, I think multitouch will take off in a big way.