I think that the examples posted by Rudi are the type that warrant an extra appreciation of thanks (in the form of $$ or €€ ). It is indeed their job to provide the basic services - when we as guests ask for something beyong the norm, I think it's only polite to express thanks.

My favorite example: I wanted to attend a world premier in Copenhagen, but I procrastinated and the performance was sold out and the D'Angleterre concierge had exhausted his usual supply. But the concierge then learned that a few returned tickets were going to be sold at the box office (no mail or phone orders). So the concierge actually went to the box offie on the appointed day and waited in line in order to secure my ticket. In this case, rather than cash, I purchased a small Hartmann belting leather card case before I left the U.S., and presented it with my thank-you card when I arrived at the hotel (especially for business gifts, I always like to give American-made products - for example, if I were giving chocolates to a European I'd take or send truffles from Joseph Schmidt in San Francisco)

As for the Berlin tickets, I think it depands on the quality of the performance (and therefore the difficulty of the tickets). If it's for a very desirable program with the Music Director, Sir Simon Rattle, conducting, I would be more inclined to tip than if it were a more pedestrian selection witl a less stellar conductor (but then that's just me)

[This message has been edited by Non-NonRev (edited Dec 25, 2003).]