Wow, you guys are way off. I know you are all kidding but just to clarify:
-No one talks, until the right person says the answer.
-There is no mirror.
-For sake of argument, lets say they are all standing in a void and there is nothing else in the room but the people and the hats.
-No one takes off their hat to look at it (the king is watching!!!!! beheadment!!!!)
No one is psychic.
The main clue lies in the line:
No one spoke for a minute or so. (and then someone guessed).
Keep plugging. And pokemon_master, I said I would give you a prize for the last one. And everyone can guess (except whoever said they knew...wdeversole I think...unless you just got it and did not already know the answer from hearing it before or looking it up

If you figured it out, go ahead and say the answer unless you want to give others a chance to guess. Maybe PM me...) as there is no prize for this one (maybe...unless I'm feeling nice

or get a mule to buy some stuff).
~Mia~
PS: ACTUALLY IF YOU THINK YOU HAVE IT, PM ME THE ANSWER SO YOU WON'T RUIN IT FOR EVERYONE. I want everyone to get this b/c it's so simple and so good (I think). If you give up, PM me and I'll tell you, but keep it on the DL!