== Ball size (seriously) == 

 This article should mention something about trackballs with different ball sizes. There a re trackballs with balls that can be operated with the thumb. Other trackballs are meant to be operated with the middle three (or sometimes even more) fingers. While logitech has the small, thumb-operated trackballs, compare with the big and really big models of Kensington. Anyway I think the article should consider this somehow. Also, the section on computer games and trackballs is completely uninteresting, as trackballs are meant as mouse alternatives and more precise, this all already implies what this means for gaming.