I'd like to add another recommendation for dealing with repetitive stress if you're a programmer: the Dvorak keyboard layout. Around 2002 I noticed tingling in my wrists and hands and immediately thought about the specter of carpal tunnel syndrome. Since I was already using an ergonomic split keyboard and a gel mouse rest I had to think of something else.

From reading on the Dvorak layout I discovered that it's designed to minimize stress on the hands. Like the most used letters in the English language are placed on the home row so your fingers don't have to travel as far compared to the Qwerty layout, vowels are all placed next to each other on the left side of the home row, even the position of letters used in common combinations are placed together. For instance, the t key is placed to the right of the h key so you can just roll your fingers to type the "th" combination. Anyway, it took me about a week to get proficient in it and a month to regain my Qwerty typing speed and the tingling in my hands has not come back. I actually used a typing games program to speed up the proficiency process. I highly recommend checking out this layout.