Another option which has worked wonders for me is the RollerMouse. You just use your thumbs to move the bar around without ever taking your hands off the keybo

Another option which has worked wonders for me is the RollerMouse. You just use your thumbs to move the bar around without ever taking your hands off the keyboard. It's a bit awkward at first, but you get used to it quite fast. [see http://ergo.contour-design.com/ http://ergo.contour-design.com/]