PrePaids in Europe this summer.

Originally Posted by borjeg

As for the Passport, you commented on something else. Of course I had a valid passport issued by the officals in my home country, but it is not valid in shops in Germany. Only passports from Germany and some former Soviet Union states are valid in German shop. These are the only ones with an address in.

Actually passports from Germany don't contain the full address only the city of residence. Only German national ID cards contain the full address. So it should be no problem buying a sim card with a passport that doesn't contain the address as long as you can give them an address where you stay.
But as Motel75 said there are probably a lot of poorly informed shop clerks who never had such a situation before because most germans use their id card.