Peripheral

for the same reasons you mention. I recall it was from 3M. I quickly found it uncomfortable, but in a different way. The portion of my hand in contact with the mouse's base (the outside of the palm) became tired from supporting the weight of my hand. If the model you're considering has a joystick long enough to grip without resting your hand on the base, I suspect you'll quickly find that as irritating to your wrist and shoulder as a conventional mouse. They'll be supporting the weight of your arm without a flat surface to rest on.

If your shoulder is giving you problems, it may be that your desk / mousing surface is too high or low. I solved my wrist issues two ways. The first was to get a Contour Per-Fit mouse, available in four right-handed sizes and three for lefties at www.contourdesigns.com. The second step was to force myself to switch hands. I went from using a right-hand mouse to a left-hand configuration. It took about six weeks to get used to it.