If you are looking for the real sort of thing (based on psychology), you should look at the work of Richard Wiseman (who consults with Andy Nyman and Derren Brown). You may also be interested in the following anecdote which I have copied and pasted from my blog rather than typed out all over again (I hope you will forgive me this laziness):
Well, I had a rather fun experience the other day after one of my shows. I had been approached by a group of people, each eager to ask me questions.
One of those in the group was a young lady, and inevitably the question she posed was along the lines of "How did you do" such and such. I explained to her that a lot of what I did during that particular experiment relied on my ability to pay careful attention to eye access cues and body language. If she was skeptical of my answer initially, the disbelief evaporated a moment later, as I had a wonderful opportunity to provide her with an impromptu demonstration of the ability to read body language to discern thoughts.
As the young lady came into the room, I noticed that she had been accompanied by a friend, who remained in the same spot at the back despite the fact that her more inquisitive friend pushed closer to me. I also paid close attention to the torso of each person. Both were fully facing me, but an examination of the feet told a story all their own. The young lady who was quizzing me had both her feet pointing directly at me, while her friend, positioned a yard or so to the rear, had one foot pointed at me, and the other at the door.
The proximity and foot cues of each party allowed me to infer details of what was going on in the mind of each person. When pressed for an example, therefore, of my assertions that I could read body language, I smiled and spoke to the young lady in front of me.
"Well, for instance, I can tell by your strong eye contact, the full exposure of your torso, and the placement of your feet that you are genuinely intrigued with your interaction with me, and could continue chatting with me for some time. By contrast, your friend, in the green shirt... (at this point, I gestured toward the young lady in the back)your friend is interested in what we are saying, but has more pressing matters to attend to and is anxious to leave. She is, however, too polite to hurry you along. As she has been kind enough to offer you a lift, I believe you ought to get going."
There were about a dozen people circled around me at this point, yet no face was more astounded than that of the young lady in the green shirt, as she confirmed that she was indeed offering her friend a ride and was in a hurry to get somewhere.
This is an entertaining sidenote to what was a very enjoyable performance. But I tell it so that those interested in the methods I employ may have some insight regarding these methods. I wish to direct any interested party to one of the best texts I have read on the subject of body language - "What Every Body Is Thinking" by the incomparable Joe Navarro.
As the example above illustrates, I can say honestly that the knowledge this book contains has allowed me to literally deconstruct a person's thought process, reading the signals that they didn't even know they were sending, and astounding them by then revealing to them what they believed to be their private thoughts held in their minds alone.
Remember, watch carefully, listen closely, and you can discern more about those around you than you would have ever believed possible!