Palo Alto is fortunate to have two excellent centers for posture training. I have taken the free introductory class each offers, and recommend both.
They are the Esther Gokhale Wellness Center, and Jean Couch's Balance Center. Both are small studios teaching a series of classes on how to sit, stand, bend forward, and walk with good posture and alignment that will eliminate many common causes of chronic pain. Both are based on a French technique called Aplomb, and the very similar content of the two introductory classes reflects this common origin.
Aplomb bases its technique on anthropological observations of people in traditional cultures. The main idea is that people in modern, Western cultures curve their spines too much, and that they lose the natural forward tilt of the pelvis. Both the Balance Center and EG Wellness have many beautiful photographs of people in Africa, Asia, and South America looking exceptionally upright and handsome with strong healthy backs, and pictures of slouching Westerners looking rather wilted and pathetic.
I don't exactly agree with everything I heard in the intro classes. Primarily, I found both to put too much emphasis on holding one ideal position, whereas my opinion is that while there may be an optimum way to sit or stand, it is also important to create variety and movement rather than holding still. Also both don't seem to support massage as therapy for pain or postural problems, which of course I do. To be fair, I got only a small sample of what they offer so maybe in the longer programs these issues are addressed.
Overall though, I think almost anyone will benefit from these classes. Whether to address an existing pain problem, prevent a future pain problem, or enhance your appearance from better posture and poise, this work will help you. Check out their informative websites, try an introductory class, and go with whichever is more appealing. I think any difference in their programs is less important than picking which teacher will convince you to change.