I was involved in a NEO exercise in the Middle East a few months back. Our role-playing evacuees included military personnel, as well as embassy staffers and their family members. I'll echo everything AROTC mentioned in his post.

DON'T cause a fuss when the Marines take your toys. (We had some role players who were supposed the act up and cause problems. The Marines did their job).

As for passports - I have never been somewhere when I thought "I wish I didn't have my passport on me." I've had one since I was 19 and will keep a current one until they put me in the grave.