I've just found this important info from MSN. I just copied & pasted it!
Photo credits From MSN also. The link is above!
There are many taboos to be wary of when eating with chopsticks. In Japan, it's considered a bad omen to insert your chopsticks into the rice bowl and leave them there for any reason. That's because resting chopsticks vertically in a rice bowl reminds the Japanese of grave markers. It's also considered poor manners to take food from the serving plate with the ends of the chopsticks you've eaten from. Instead, turn your chopsticks with that side toward you, and then pick the food up. In China, among other countries, pointing a chopstick at someone is considered rude.
2. Visiting mosques
All visitors — Muslim and non-Muslim — must remove their shoes before stepping into a mosque. Visitors should also follow customs for dress when visiting a mosque. Men should wear long pants and long-sleeved shirts. Women should cover any bare skin, although the strictness of this guideline varies from country to country. Women must wear a head scarf; however, if you don't have one, most large mosques will have head scarves that you can borrow at the entrance.
3. Giving flowers
If you plan to give flowers as a gift in Ukraine, be sure the bouquet contains an odd number of blossoms, as even-numbered bunches are customary for funerals. If you're bringing flowers as a hostess gift or to celebrate a birthday or other special occasion, you should avoid yellow flowers or Easter lilies, which are also reserved for funerals. When invited to a Ukrainian's home for a meal, you may want to play it safe by bringing a bottle of imported liquor instead.
Train passengers in Cheshire, England, can run afoul of local authorities if they linger over long, romantic farewells. Officials at Warrington Railway Station posted a "No Kissing" sign to stop smooching couples from holding up other commuters. However, if you need to say a longer goodbye, you still can … in the newly designated "Kissing Zone."
Although Egyptians are considered to be extremely friendly and hospitable, their cooks must have very tender egos. When traveling to Egypt, don't put salt on your food, as doing so is considered an insult to the chef. Fortunately, Egyptian food is usually quite flavorful, thanks to abundantly available spices and the use of garlic, onions and other aromatics.
6. Visiting churches
If you're planning a trip to Italy in the warmer months, be sure to pack more than shorts and tank tops. Visitors to the country's churches and cathedrals are expected to dress modestly, which excludes short shorts or sleeveless tops for both men and women. Expect your dress to be scrutinized at the door by guards or other parishioners; to avoid being called out, pack a shawl, sweatshirt or other layer you can slip on before entering the church.
7. "V for victory" sign
Don't make the "V for victory" sign with your palm facing inward in Great Britain, as it's considered to be both a gesture of defiance and an insult. According to popular legend, the two-fingered salute derives from the gestures of longbowmen fighting for the English army during the Hundred Years' War. As the story goes, the French claimed that they would cut off the arrow-shooting fingers of all longbowmen after they had won a decisive battle. But the English came out victorious and showed off their two fingers, still intact.
8. Insulting the king of Thailand
Thais deeply revere their 80-year-old King Bhumibol Adulyadej — some see him as almost divine and carry his image on talismans to bring good luck — and insulting him is a crime known as lese majeste, punishable by imprisonment for up to 15 years. The law, a throwback to the era of absolute sovereign power, has led to Web sites being censored and at least one foreign writer having been arrested.
9. Clinking beer glasses
Hungarians don't clink beer glasses or bottles when they're making a toast, due to the tradition of remembering soldiers killed in the 1848 revolution against the Habsburg Empire. Legend has it that after Austrians celebrated the executions of 13 Hungarian martyrs by clinking their beer glasses, it was decreed that no Hungarian would toast with beer for 150 years. Even though it's now more than a decade after the end of that time period, old habits die hard. For travelers, this taboo may be easier to remember than how to say cheers in Hungarian: "Egészségedre."
10. Cleaning your plate
The "clean plate club" doesn't exist in Cambodia. If you eat everything on your plate, it means you still want more and signifies that your hosts have not served you enough. Cambodians enjoy a strong sour taste in many of their dishes, especially through the addition of prahok, a pungent fish paste. This is an acquired taste for most foreigners, so maybe cleaning your plate isn't a big risk after all.