I never tip. As far as I remember the tip is included in the paycheck here. Tipping is not common in Denmark, unless you've been to a restaurant and you think the service has been good - even then you can neglect to tip and it's still cool. In other words, you're not expected to tip.

Therefore I had a bit of a hard time remembering to tip when I was in the US last year. But hot damn, you people tip everything over there!