What is the correct pawn promotion procedure? 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?
The procedure is (FIDE rules): move the pawn to its promotion square, then replace it with the piece you want. You can take it from the captured pieces yourself, your opponent does nothing. If the piece isn't readily available, you can stop the clock and ask the arbiter to bring one. Your choice of piece is only finalized when it touches the promotion square. See the Laws of Chess

An upside down rook is a rook. A pawn on its side is a pawn, and thus an illegal move.

The FIDE rules will be changed a bit in the upcoming July 2014 Laws of Chess, see e.g. this ChessCafe "Arbiter's Notebook" column by Geurt Gijssen, who is involved in the rules changes. From July, it will also be legal to remove the pawn from the board without moving it to the promotion square (followed by putting the piece on the promotion square), and it will also be legal to place the piece first and then remove the pawn. Those used to be illegal moves.

And also from July, if you move the pawn to the promotion square and then press the clock, you've made an illegal move (that's already the case now), and as usual the pawn counts as touched and you will have to promote it in the legal way, but you will be forced to promote to queen. Apparently people were using this illegal move and the delay it will bring as extra thinking time to decide which piece to promote to.

As you can see there are some fiddly details that may be different with USCF rules, but I don't know those.