Instead of a computer mouse, I use a trackball for a pointing device. I find that it is much healthier for my wrist, elbow, and shoulder.
The only downside I experience is that I often accidentally click the right-button. This happens because I have fairly large and heavy hands, and the trackball I use is ergonomically designed to keep the wrist at an angle (instead of flat).
What clever techniques will reduce the number of erroneous right-clicks that I perform?
Edit: Here is a video review of the trackball. At about 1:40, you can see how the reviewer's hand is positioned and how it could accidentally press the right-button with just a little pressure.
Also, here are two static images at different angles: