Well, I still have friends in the US, and I guess that the current residents of our rental house would probably not bother.
What if I would want to buy some "american" apps (are there apps that only show up depending on your store location?). Would I need to get some US itunes cards or would one bought in a German store work too? I would think that apple has some serial numbers on the cards maybe indicating the location???
Thanks again for all the great answers so far.