We've been using a mouse and a keyboard for ages now. It's an axiom with contemporary computers: computer, monitor, keyboard, mouse.
Did you ever consider using two pointing devices instead of one? With one mouse, you can manipulate the mouse and keep one hand on the keyboard. But in most cases you're so used to typing with two hands, that you're mostly incapable of using your keyboard with one hand anyway.
I'm used to using my two hands simultaneously, sometimes doing different things each. Could there be a way to put that in action with two pointing devices?