All throughout the field of NLP and Ericksonian Hypnosis there seems to be a premium placed on developing what would be referred to as 'Advanced Calibration Skills'. There are even a couple courses that claim to teach these skills. Never having been on any of them I can not comment to how worth while they are.
I have seen demonstrations of detecting VAK accessing cues from NLP, a few demonstrations of detecting Submodalities and Meta-Programs, and I have always found them interesting (but never terribly pragmatic during the course of a regular conversation).
Lately I have been focusing Micro-Expressions and Subtle-Expressions. If anyone is interested at www.humintell.com there is actually a training program that you subscribe to that allows you from the comfort of your home develop your skills in reading them.
The work of Joe Navarro, I have found very fascinating as well as useful and I would recommend it to anyone.
As of late I have been looking into Cold Reading... I'm convinced that some of Milton Erickson's advanced calibration skills can be attributed to an ability to cold read people. I don't know that he was doing it purposefully as such but I do think that it is an interesting by product of his natural ability to speak to people in such 'artfully vague' terms as has been described.
I would absolutely recommend to anyone interested in working with people in any fashion to learn how to do cold reading.