Different cultures have things that they find rude.  Here in Vietnam is it not rude to do the following:

• eat with your mouth open
• stare at people
• Slurp when eating food
• spit in public
• pick at your toes
• Pick lice out of your hair on the street and restaurant
• cut your finger nails at work
• burping
• urinate in public, especially men
• Men walk around in their underwear
• When it is hot lifting your t-shirt up over your stomach – men only
• talking in movies
• answering phone calls in the middle of meetings
• Asking how old you are
• OK to touch people
• OK to be in people’s personal space
• Jumping the queue/line
• Taking pictures of people without permission