While I was unsure of how much I would like having only one mouse button on my iBook,
I quickly adjusted.
My normal hand position now is to keep my left hand on the bank of function keys
at the bottom left of the keyboard, and to use my right hand on the touchpad/button.
The nice thing about having one large button, is that it lets me avoid having my right hand
in a fixed position - I can move it around and be able to hit the button at any time without
having to move it back to a home position.