Wrist Pain
dstorrs: There's plenty of good suggestions in here, so I'll just add a small pointer:  SmartBoard keyboards from DataDesk Technologies.  "Oh, go buy an ergonomic keyboard!" sounds like trivial advice.  A few years ago, I had wrist pain--not as bad as yours, but plenty sufficient to scare me.  I bought this keyboard, and it vanished.  They are also durable:  I've had one for 5-7 years, I use it 8-10 hours a day every day and it's just starting to lose some keycaps.The only problem is that they are almost impossible to find.