I've been on the computer a lot in the past year, mostly because of work, but then to unwind I'd come home and post on various websites and/or play solitaire. I believe I've developed a mild case of carpal tunnel/tendonitis in my right hand (mousing hand). I did some research and I do believe the mouse is the biggest contributor to this.
One thing I've done to try to alleviate the amount of mousing I do (at home anyway) is to purchase a pen pad (~$75 - 100). Another thing I'm doing is making sure I'm not moving my wrist back and forth when mousing - I'm moving my whole forearm so wrist stays stationary - and also, I've taped some foam directly under my wrist and secured it with an Ace bandage. This will help keep my wrist parallel with my forearm. One of the causes of carpal tunnel is dropping the wrist or flexing it up; this puts unnecessary compression on the carpal tunnel. When you type (or mouse click) a lot, the tendons can become inflamed.
One of the biggests indications for me that this was becoming a problem was tingling sensations in the thumb and first three fingers (only half the ring finger tingles; so all fingers except the pinky), and also a dull pain in my wrist when I tried to lift heavy things, especially if I flexed my wrist at all. A sure sign one is developing carpal tunnel is wrist pain that wakes them up at night.
Just thought I'd share to hopefully save anyone else from unnecessary pain. I'm still researching ways to deal with this, if anyone else has any ideas, let me know.
p bean