Hi all. I think I have a quite interesting question. But before I present it, please take a look at the following position:

Here white (on the move) can mate in 2. Obviously, not with c8=Q?? as it's stalemate. The correct way to promote is c8=R!! where Ka6 is forced, so Ra8# can be played.

Now, please imagine this situation on a tournament for instance.  Let's say that white has already pushed c8, and then touched a Queen next to the board, only to realise that promoting to a Queen leads to an immediate draw. Can he change his mind and put a Rook on the board, or is he forced to make a mistake due to the rules of touched pieces?

This is a really interesting question.

And what if he pushes the pawn, and announces "Queen!" without touching anything?

f it says queen it's not counted as a move, it happened. It happened to me too that my opponent sayd check before making his move and he could move to  a square wich didn't was check according to the arbiter

From FIDE rules:

4.4	If a player having the move:
	a.	deliberately touches his king and rook he must castle on that side if it is legal to do so
	b.	deliberately touches a rook and then his king he is not allowed to castle on that side on that move and the situation shall be governed by Article 4.3.a
	c.	intending to castle, touches the king or king and rook at the same time, but castling on that side is illegal, the player must make another legal move with his king (which may include castling on the other side). If the king has no legal move, the player is free to make any legal move
	d.	promotes a pawn, the choice of the piece is finalised, when the piece has touched the square of promotion. So you can pick anything up as long as you don't put it down, it sounds like.

 

From the FIDE Rulebook:

Article 6: The Completion Of The Move

6.4

in the case of the promotion of a pawn, when the pawn has been removed from the chessboard and the player's hand has released the new piece after placing it on the promotion square. If the player has released from his hand the pawn that has reached the promotion square, the move is not yet completed, but the player no longer has the right to play the pawn to another square.

So, we see that a verbal announcement is irrelevant.Only when the player releases the newly promoted piece on the promotion square, is the move considered complete.

If it's in there twice they must mean it.

Baseball could learn a lot from the concise chess and soccer rules. Go, Giants!

Related question: what if there is no such piece available? For instance, promoting to a third knight? Can you use any captured piece to represent the desired promoted piece?

No, only a knight can be used. If there's no knight captured, the clock can be paused and the players can call the arbiter or simply borrow an already captured knight from a nearby board.

From an old thread (re USCF rules):

"There is also mentioned the oft-used provisional upside-down rook (for a queen) as acceptable but I suppose it could stand in for a knight or bishop as well. I suppose once the piece is declared in those circumstances with the upside-down rook that any verbal designation would be final."

Upside-down rook is OK for a 2nd Queen.

It would be fun to see a composition with the pawn promoted to a pawn as the only way to win/draw (this used to be legal I think)

If there are say 10 seconds left can a player say queen and leave it as a pawn, representing a queen?

Well, when I was in a local tourney, our arbiter said that no upside-down-rooks can be used, because there's no such a piece in chess: it can be a source of controversy or cheating because the player can say for example c8=N and a few moves later move the upside-down-rook as a queen, and the arbiter can do nothing about it, because it can be used as a knight and a queen as well.

Still better to stop your clock and avoid misunderstandings

Re USCF rules:

"The rules also say to contact the td if no appropriate piece is immediately available. I don't see anything about verbally designating a piece for the promoted pawn, in fact they say that if the pawn is left on the square with no replacement the opponent merely starts the clock of the promoting player."