Lisa can't use a mouse or trackball at all and very much likes touch pads, but can't stand tapping or any of the other fancy features they've inflicted upon some touch-pads. She wants to use the touch-pad solely as a pointer, not as an additional mouse button or anything else. This is why we went to the extra effort of getting a special keyboard for her new desktop that replicates the layout of her laptop computer. (The new desktop PC is actually an old surplus machine from work that I was able to get for cheap when it was retired; many years ago, it was actually my primary modeling computer. I reformatted it with WinXP down to bare metal and it runs like the wind since there's almost nothing installed on it.)