This may be a frivolous question, as I believe that most chess players are good sportsmen, but I was wondering: what is the technically correct procedure for promoting a pawn to a queen? Do you ask your opponent to put the queen on the promotion square, or do you take it from his pile of captured pieces yourself (provided of course that queens have been exchanged)? If you have to ask your opponent, what happens if he takes his time (as in the case where you may be in time trouble, for example?). If you have to take it yourself, are there rules around where you are allowed to keep captured pieces (the absurd situation being that your opponent hides the captured queen when the promotion becomes evident).
Similarly, I vaguely remember that there was some professional game that got delayed because they couldn't find a second queen after one of the players promoted while still having his original queen on the board. This puzzled me a bit: in my school days, we would either use an upside-down rook or even a pawn rested on its side to mark it as a queen - is this for some reason unacceptable in tournament play?