be aware that all Americans are now required to have a valid passport to FLY into Mexico.  you can still enter by land or sea for a limited time with your valid drivers license of government issued photo I.D. 

if you're planning a trip soon, head on down to your local Post Office to apply for your passport.   we strongly advice to pay the extra fee for express service.  you will receive your new passport in as little as 2 weeks.   some cities may differ in processing times depending on the workload of a particular office.

for more detailed info, please visit the U.S. Passport Agency at this link...

http://travel.state.gov/travel/cbpmc/cbpmc_2223.html

hasta pronto!