This has probably been discussed to death, but I was recently in Berlin and over 5 days & saw 4 blatant examples of an american being an american in a foreign country. It grated on my nerves. Instead of posting a story about the people who wasted time yelling and arguing, I'll post the tips that would have avoided it: - If you have a combination museum ticket, it stands to reason you probably shouldn't wait on the long line to buy tickets. Go to the door and show them the ticket. Nobody is coming to escort you in when you wave your hand. - Don't assume that every tourist destination worker speaks perfect english, whether it's a hotel or an attraction or a ticket desk. Start off speaking politely using simple words and discover the level of english the other party has. Adjust your attitude and use of slang accordingly. - Don't assume that a hotel cleaning staff member doesn't have a disgust threshold. If you would see an item in a porn film or in an operating room right after an operation, don't purposely leave said used item out in the open of your hotel room and expect the staff to deal with it and/or ready it for it's next use. That's not what they are there for. - Don't get upset when you decide to purposely ignore local laws/customs and then lose a chunk of your vacation paying for it. Getting nailed for something minor in your own country is one thing. Getting nailed for it in another country where you don't speak the language is quite another. If anyone wants a complete rundown, I'll be happy to send it. Travel with respect, please!