Taking a break every hour or so is also good for avoiding RSI. I had RSI pretty bad several years ago, but have recovered completely. Part of the solution was using a break program to help me remember to take breaks for stretches. Currently (OS X), I'm using RSI Guard, which does what I want. More details on my RSI problems and solution here: http://henrikwarne.com/2012/02/18/how-i-beat-rsi/