Having just developed a bit of a sore wrist on my fretting hand I thought I'd pass some information on to everybody on what looks a good website for all things to do with posture and playing guitar.

http://www.tuneup.com.au/node

I'm not sure if my sore wrist is solely due to my guitar playing or if it's something to do with the fact that I've just laid a patio and also helped my daughter move house last week....
I've never done a heavy job so it's probably just all too much heavy use in the last few weeks. Time to ease up a bit just to be on the safe side.

Hope this info helps others.