Logitech do nice trackballs with side mounted balls which lets you use just your thumb to control them. The build quality isn't very high though, they need replacing every 2-3 years. Usually because one of the buttons starts to double click. I'm using a Speedlink one at the moment with a logitech ball in it. Includes 2 extra buttons and a DPI switch which is pretty handy.
Classic IntelliMouse 2018 - Microsoft brings back IntelliMouse
Aaron Cruz
Joseph Collins
Lots of glass makes it feel larger and has the nice bonus of being observed by other people at all times. Can't scratch your balls and give it twenty minutes before you do some work if you have 30 people watching your every move.
Aaron Peterson
I'm pretty sure he's referring to the combined speed and precision