Ryan,
I don't know what the drinking age is in Brazil or Mexico. It might be advisable for you to be sure before you trek down to Tijuana. Eat a fish taco for me! Regardless, keep in mind for the next few months that the two parts of the United States where the drinking age is still 18 years are Puerto Rico and Guam.
Add me to those curious if you got an e-mail address or phone number for the EWR President's Club patron who helped start this thread.