Body language, is one thing, that will definetly put you above your "competition" as long as you dont take it so literally. First of all, what is body language? Body language is a term for communication using body movements and/or gestures, know anyone who "talks with their hands"? That is exaggarated body language.
Body language is one of the simplest things to learn in life. Actually, only thing you really need to do in order to learn body language properly, is to train your eyes to notice certain subtle things people do, of course you need to have a knowledge of what those different gestures mean, but the basic idea is to just observe. Example: Have you ever seen how women bite their lower lip, when talking to a handsome men? Or looked at a couple talking? They are usually complete mirror images of each other? Many women know these things by nature by the way. It is the "feminine instinct" which can smell your bad deeds a mile away. Exactly why trying to act extremely "cool" will look more like an awkward attempt to make an ass of yourself.

How about this? Who crosses his/her legs first in the dinner table? There are simply THOUSANDS of this kind of little gestures and by understanding them, you definetly have the edge on everyone.

Of course, I am no professor in these things. Just a jack-of-all-trades. But these guys are! Read, and learn.

Never be lied to again!

Here is a cheap guidebook for all women about body language! 

There are also a lot more from ex: Amazon.com and Ebay. 
One very strong book is The Body Language Bible by Judi James. 

If I have piqued your interest, search around. You will be glad you did!

Just a little sidenote here. Hypnosis, is also one form of body language. It is mimicing the other person, breathing at the same time, blinking together etc. 
If you want to know more, this book especially is for you:

Complete guide to hypnosis

Of course, this is so powerful, that I suggest you get this only for your own protection.