If you are considering the Philly mint please be aware of the following:
1) No cameras are allowed. This includes anything that can take a picture, including cell phones, mp3 players, etc. This is much stricter than simply not allowing picture-taking.
2) There is no place nearby where you can stow your camera (there are no lockers or anything else). The guards will not hold your camera for you while you go thru the mint.
4) The above opinion is mine. No insult intended to anyone who liked the mint.