Regarding stretching, I found the book Conquering Carpal Tunnel Syndrome to be a huge help. It has lots of suggestions for kinds of stretches to do based on the kind of work you do, but my big takeaway (and according to the author, the most important part) was how to do the stretches: only stretch until you barely feel a stretch, then hold there until you feel a sense of release. In my experience that was more effective than the “stretch until you feel a good strong stretch” strategy.

https://www.amazon.com/Conquering-Carpal-Syndrome-Repetitive...

Switching to a Kinesis keyboard has helped my hand/wrist pain quite a bit. It seemed to be steadily getting worse, and disappeared after using the keyboard for a couple weeks.

Another thing that helped is the book Conquering Carpal Tunnel Syndrome[0]. It has a good set of stretches to do categorized by what's bothering you.

Even more impactful IMO, it teaches a technique they call the "stretch point": very gently & slowly stretching until you feel the first hint of a stretch, then pausing and waiting for the feeling to release, over and over. Versus what I was naturally doing before, which was to stretch until I really felt it, and hold for a while. The theory is that the slow/gentle stretch+release pattern is more effective for the smaller muscles and less likely to damage them.

[0]: https://www.amazon.com/Conquering-Carpal-Syndrome-Repetitive...

I use the Microsoft Natural keyboard, and this is how I solve the mouse distance problem for myself:

http://i.imgur.com/3OMpedd.jpg

I just remove the numpad keys, and then tape my ergo trackball down to it. Works like a charm and allows me to keep my wrists in neutral position at all times.

I've definitely struggled off and on with RSI over the years and this book has been really helpful in keeping me limber:

http://www.amazon.com/Conquering-Carpal-Syndrome-Repetitive-...

The other thing that's helped me is going to the gym and doing light wrist curls (and reverse wrist curls) at least once a week.

This book contains a lot more exercises in the same vein:

http://www.amazon.com/Conquering-Carpal-Tunnel-Syndrome-Repe...

Changed my life -- no more typing pain.