Christopher Hitchens wrote an article for Slate a week ago pointing out that a recent (successful) assassination in Saudi was carried out with a body cavity PETN bomb.
Supposedly the assailant was thoroughly searched and finding nothing suspicious , the security people let him approach the prince. The bomb was detonated by remote control, through a message or call to his cellphone.
http://www.cbsnews.com/stories/2009/09/28/eveningnews/main53...