I've been looking for a new mouse (Mighty Mouse just doesn't cut it for comfort, my wrist drags on the desk and causes pain after prolong use) and have been wondering about Trackballs. Just wondering what everyone thinks of them and if there are any good ones that work with Macs. And also, if I can't find one that I like, I might get a mouse, I need one that is relatively cheap (Under $45). And I was wondering what happens if you have one with more than the normal 2 buttons, do you have to install special software for the other buttons? Thanks.