I use a Kensington Expert Mouse (it's actually an optical trackball, despite the name) which fits very well with the finger arrangement you describe. I use my l

I use a Kensington Expert Mouse (it's actually an optical trackball, despite the name) which fits very well with the finger arrangement you describe. I use my little finger for the right button, though; I don't know if that's a deal breaker for you. http://www.kensington.com/kensington/us/us/p/1444/K64325/expert-mouse%C2%AE.aspx http://www.kensington.com/kensington/us/us/p/1444/K64325/exp...