I talk about the importance of understanding the culture that you are presenting to in my "Tips on giving a great [technical] presentation." 

I noticed an article on on CNN today about the correct use of humor overseas.  I try to use humor when I'm giving a talk, but I can tell you that it's true - you REALLY need to be careful and run EVERY joke by a friendly (and not easily offended) native before you try them out on a crowd. 

This article seemed particularly well-timed, as I'm poised on a brink of a trip to Morocco, through Spain to meet my Arabic and French speaking friends and their audience.  I'm travelling with a Zimbabwean and will see my good Turkish and German friends while I'm there.  God Willing (InshaAllah!) there will be no international incidents...at least none caused by me. :)

Here's some choice tidbits I enjoyed:

• Did you hear the one about the American businessman whose tame joke drew a hilarious response from his Japanese audience?
  The American, curious why they liked the joke so much, later asked his official translator, who replied: "The joke was not appropriate, so I did not translate it. I simply said: 'The gentleman has told a joke. Please laugh.'"
  It is not uncommon for interpreters to avoid translating humor.
• The American trademark is to start a speech with a joke, she said. "When foreigners speak here, they also want to start with a joke, but that never works because the worst thing you can do is mimic other people or the nuances of their culture."
• "You may think you know a nation after spending a lot of time there, but you cannot be fully up to speed with the latest happenings, thoughts, etc, and, sure as heck, you'll choose a no-go subject matter for a humorous quip just when you are near to closing the deal."
• For Chinese, Japanese and Malaysians, a 'masking smile,' with corners of the mouth turned down, is a polite way of letting you know what you are doing is not appropriate.
• Basic arm folding is seen as putting a barrier between you and the person who is talking.
• [A] story of a newly promoted American soldier at an embassy party celebrating the Allied victory at the end of World War II:
  "A Frenchman stood up to give a toast and a British officer followed suit. The young major, who had studied French at West Point, was pushed front and center to represent the U.S.
  "Unable to think of a toast, he chose a poem intended as a tribute to a child and his mother. 'The best years of my life,' he recited, 'Were spent in the arms of another man's wife.'
  "His vocabulary was a bit rusty, however, and he confused the French words for arms and legs.
  "Needless to say, the hosts were offended and the mortified young officer was "spirited away to his troopship... just before the dueling pistols came out."