The author teaches 5 simple negotiation techniques - Get perspective of the situation by 'going to the balcony', step to the adversary's side, re-frame adversary's thoughts and beliefs, build them a golden bridge. If any of the above 4 techniques don't help you - use power to educate your adversaries. The author has cautiously avoided using the word 'adversary'. He recommends everyone to take a 'co-operative' approach and not a 'manipulative' approach.
If there is one thing that is more important than any of the suggested techniques - it is PREPARATION. "The best place to make mistakes is in rehearsing with a friend or colleague, not in negotiating for real". This echoes Jim Champ's "Practice sessions provide you an environment to fail safely" theory.
The importance of having a BATNA (Best Alternative to a Negotiated Agreement) is re-enforced in this book. Overall, this is a very good book to read to improve your negotiation skills.
Author's website: http://www.williamury.com/