It makes sense when you're working directly on a screen. I've had the opportunity to use the Wacom Cintiq in its various models over the years (and would love to actually afford one of my own), and for graphics and photo retouching, it's the most natural way to work. It's a lot like working at a drawing board or an easel (depending on the tilt angle you use). Not so much if what you're doing is keyboard-centric, though.