Neurolinguistic Programming
There are some interesting articles about how Barack Obama is using Neurolinguistic Programming in his speeches to "hypnotize" the audience. This may be a bit of an exaggeration, but the techniques he employs are very persuasive.
NLP has been discussed as a technique to help people interview better. It is a way of building a connection with the person listing that is much stronger and more persuasive. One of the core techniques that is taught it mirroring. With this technique the job seeker attempts to copy the tone, pace and rhythm of the interviewer.
By mirroring, the goal is to cause the interviewer to feel more comfortable and identify with the job seeker better. This is achieved by making the interviewer hear something that sounds very much like their own speech.
You can also mirror someone's eye contact. Some people find it uncomfortable to have someone stare at them. Despite this, we all try to make good eye contact in an interview. Often this means staring at the interviewer. If the interviewer is uncomfortable with this, you're going to have a tough time winning them over. Watch their eye movements and the amount of time they spend making eye contact with you. If they only look at you 20% of the time, you may make them feel more comfortable if you look at the office surroundings during the interview to avoid staring continuously.
There are much more sophisticated NLP techniques. Some involve using hand gestures to tie concepts and emotions together. Others involve using specific language and story telling techniques to change the way the listener analyzes what is said.
Most of these techniques take work to master. A few can be used without much effort. Pay attention to how an interviewer sits, the pace and tone of their speech, the amount of motion and hand gestures they use, and their eye contact. If you notice something inconsistent with your style, adapt your style to the interviewer's.
The key is to keep it natural. Don't change your style so much that you look like you are acting. Also, don't try to copy something that doesn't make sense. For example, if the interviewer has an accent that you do not have, copying the accent is going to far. Mirroring the pace and rhythm, though, can be very effective.
If you want to learn more about NLP, check out http://www.nlp-now.co.uk/nlp-what.htm
If you want to see NLP in action, read this article on how Obama is using NLP: http://www.pennypresslv.com/Obama%27s_Use_of_Hidden_Hypnosis_techniques_in_His_Speeches.pdf