Faux Pas, Nation by Nation

Wikipedia has useful and amusing articles on national expectations of etiquette. Examples:

• Australia & New Zealand: "When riding alone in a taxi, it is considered more polite to sit in the front passenger seat next to the driver. However, it is not considered impolite for women to choose the back seat if the driver is male, especially at night."
• European countries: "Avoid hand gestures with which one is unfamiliar; many hand gestures are impolite. Also, some gestures have different meanings in different cultures. For example, a variation of the thumb-to-index finger "okay" sign is an obscene gesture in some European countries."
• Scandinavia: "Not finishing one's food implies that the taste or quality was poor and it could not be eaten or the host does not correctly serve the quantity of food one needs."
• Middle East: "Among Muslims, the left hand is reserved for bodily hygiene and considered unclean. Thus, the right hand should be used for eating. Shaking hands or handing over an item with one's left hand is an insult."
• India: "It is considered immature and hoggish to open a gift in front of the person who has given it. Gifts are opened in private."