Passports
A valid, current passport is a requirement to travel between USA & Mexico. (In the event your passport is misplaced or lost during your trip, its good to travel with a photocopy, or scan your passport and save it to a secure online account.)
Resources for US citizens:
Apply for a passport
www.travel.state.gov/passport/passport_1738.html
How to get your passport in a hurry:
travel.state.gov/passport/hurry/hurry_831.html
Passport Renewals
travel.state.gov/passport/renew/renew_833.html

