Former chief United Nation's hostage negotiator Giandomenico Picco. He has written about his experiences in the new book "Man without a Gun: One diplomat's secret struggle to free the hostages, fight terrorism, and end a war." (Times Books) Picco helped negotiate the release of more than a dozen western hostages being held by Islamic militants in Lebanon. He currently serves as president of GDP Associates, an international consulting firm in New York city, and is founder of the Non-Governmental Peace Strategy Project based in Geneva, Switzerland.