I have been reading his books recently and I highly recommend them as a very Mustachian way of dealing with chronic pain/general posture/overall health/etc
I originally started reading them because of a slow to heal rotator-cuff injury - after doing the exercises for the past 4 months I notice a lot of unanticipated improvements as well.
I only read them after Tim Ferris mentioned him in the 4 hour body. I don't think Tim gives this guy enough credit - actually after reading Pete's books I would recommend Pain Free over the injury proofing chapter in the 4 hour body.
http://www.amazon.com/Pain-Free-Revolutionary-Stopping-Chronic/dp/0553379887/(its actually a little cheaper at WalMart - thanks invisible hand! - but I have a Prime membership so I like amazon.)
I have also read his other books and they are very informative and cover a few minor points that Pain Free doesn't address - but if you are only interested in one go with Pain Free. It is most straightforward with: "Pain here? - do this to fix it."
If you don't have pain it is still a great book on how interconnect our whole body is - and how to make sure it runs "perfectly" until you die.