Many thanks to Zed for bringing it up the topic. I think it is always good for the programming community to hear different views on it. As we rely more and more on computers, mobile devices, etc., we're going to see these sorts of injuries more and more and I'm not sure the medical community knows how to deal with them yet.
I read HN sometimes and there are so many people doing full time jobs, then coding at home, then playing guitar on top of that! It is depressing to read because I'm lucky if I can make it through lunch without my arms hurting some days. I don't think people in my camp speak up enough (partly because we are trying to type as little as possible). I haven't played my guitar in years while I try to cope. I've been to some physical therapy, but found that it didn't improve things much short or long term. If you do visit a doctor (which you probably should), just be aware that they may suggest surgery. Personally, I don't think that is the answer to RSI in most cases.
I weight lift occasionally but I can't tell whether it is helping or hurting. I've always been curious about yoga, I just need a kick in the pants to get started. So, there's my personal story.
As far as advice, I don't have much since I haven't actually found something that works well for me. I read "It's NOT Carpal Tunnel Syndrome" which was an short, interesting read, but ultimately didn't help me with my particular problem. It does have good general advice, a section with stretching exercises and nerve glides, etc.