laptops - eraser pointer? touchpad? (Score 1)

i use a laptop at college, and am planning on buying a new one shortly. im not worried about the type of pointer, as i can use just about anything pretty well. i have a cirque pad for my desktop at home (great device), and an eraser pointer on my laptop now. is there any difference between the devices from a RSI point of view? is one preferred over another? obviously a mouse has got to be the worst (sometimes it brings on pain within minutes), and certainly a touchpad involves more motion than the eraser pointer. besides trackball, has anyone had any long-term experience with laptop pointing devices and RSI problems? thanx --andrew