This is a remarkable video of Esther Gokhale's talk at Google about posture:
The Gokhale Method
Its remarkable how evolutionary 'correct' posture changes the way you look and feel.
The nice thing about Esther is that she does a great job of explaining the 'why' of how to fix your posture. One of the most remarkable points she makes is comparing illustrations of the spine from a 1990 and a 1910 medical textbook, which allows you to see how rapidly posture has deteriorated in the last 100 years, to the point that doctors are promoting a harmful ideal (the 'S' shaped curve) in a reflection of society's deformed average. Her innovative system lets you fix your posture, and she shows how its not particularly difficult, and in everybody's reach.
(I have an opinion that medicine is so S and F influenced that it is largely screwed up, and likely to be radically reformed in the coming century. It is almost exclusively symptom based, which is a classic S approach, as opposed to treating causality. The posture debate is a classic example, others include nutrition, obesity and depression, which I will tackle in future posts.)