To the English who are insulted that waiters and waitresses have mentioned the US tipping customs, you should look at your countrymen. Too many waitstaff have been stiffed by those with "funny accents" like yours. In fact, I have heard that restaurants in Times Square, which are filled with European tourists, are adding tips to all bills.

Now you can say the US tipping custom is dumb, ineffective, etc. fine, but the simple fact is that if you are visiting another country you need to abide by the customs of that country, end of story.