Asuming that the number of notebook style PCs continues to rise, your fingers, when on the keyboard are actually pretty close to the screen, often closer than they are to the mouse. So you would just move your have foreward some 10 or 20 cm and every once in a while.
To touch on a cell in Excel or mark a couple of words in a text processor. Maybe use two fingers when in Photoshop or AutoCAD. Well, for the later maybe a mouse is necessary, but that's what W7 will be around for for quite a while.