I don't know a ton about the long neck women... but they are part of a tribe that exists in SE Asia (Thailand, Burma, ...Vietnam too, I think). Traditionally, these women would put golden rings around their necks... stacking up so many that their necks would be stretched longer. It is very painful... and the tradition began disappearing... until they realized that it was a good tourist attraction. Now, many women are wearing the rings around their necks again... some even being forced to by the government - all for the tourists.
It was very interesting... and all the women were polite enough to let us take photos... but a piece of me felt bad about even being there and being a part of prolonging this 'tradition'.