This Trackball is the best input device there is. it is great for fine detailed work and can be adjusted/customized for course movements as well. It has a scroll ring around the ball that makes scrolling very easy and four buttons that are completly programable. No more carple tunnel or hand cramps. It even comes with a hand rest that makes it even more comfortable, USB hook-up or even a wireless one. Depending on how much fine motor control he has in his hands Kensington has a 10 button programable trackball that would render your keyboard all but useless.
I hate mice!!