Here's a list of cultural awareness tips from VisitBritain ("Marketing Britain overseas and developing the visitor economy"),covering Japanese, Argentinians, Hong Kong and mainland Chinese, Arabs, South Africans, Brazilians, Indians, Mexicans, Canadians, Australians, New Zealanders, Koreans, Belgians, and Poles. (Apparently it's not possible to offend an American.)
Here's a taste:
• Be careful how you pour wine for an Argentinian. The whole process involves a number of social taboos and unless you understand them you could insult someone. For example, pouring wine backwards into a glass indicates hostility. Don’t be offended by Argentinian humour, which may mildly attack your clothing or weight.