What documents do I need traveling from San Diego to Mexico? Thanks so much

Assuming you are a US citizen, I would say all you need is your passport. That's what I take with me when I travel abroad.

I'm traveling next week and I haven't heard that I'll need anything else.

If you don't have a passport, you should check with the airline or the US consulate, etc; after 9/11, I'm not sure you can travel without one.

Enjoy Mexico, it's fabulous.

Next time you are near a bookstore, just pop in and take a look at a current travel guide (Fodor's is one) and check entry requirements. This will take about five minutes. Better yet, for a few bucks, buy one, use it for the whole trip--info. on routes, buses, what to see and when, how to get there, a selection of hotels, restaurants--varies depending upon which book you choose, etc. I can't imagine going to a foreign country without a travel guide. They will save you more money than they will cost. (Incidently, I don't work for Fodors--it's just common sense.)
In the past, and maybe still, a passport was not required for Mexico--a birth certificate (original,not copy) and photo ID would do it, but that will (or has) changed. A passport will be required but I don't know when this goes into effect. You could also call the passport office of your local Federal Building. They will tell you. If I am not mistaken, the new passport regulation has more to do with getting back into the states than into Mexico. The new requirement is US law, not Mexico's. Also, on returning, you will have to go through imigration and customs at your first stop in the US. Not having a passport will take longer. If you have another flight to catch and a tight connection, this could matter.
Norm

You can still get into Mexico from the US with a driver license and your birth certificate (OR of course a passport).

This is scheduled to change in the near future but has not yet. I suggest checking U.S. and Mexican government websites for verification of this information.

I suspect that by the time the guide books are published, the information about passports and visas could already be out of date. That said, I'm a big fan of guide books; as much as I love the internet it's just not a substitute for holding them in my hand and packing them around in the year ahead of a trip. I usually buy more than one for an area so I can get different opinions.

Here's a website to check for current passport and visa information:

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

Happy trails!

Imhpo, I cannot imagine travelling without a Passport.
M (SMdA, Gto.)

Passport is the best ID you can have, traveling or not.

Anyone who can travel internationally, can afford a passport (some people say--Oh, but they are so expensive!). On any trip you take out of the country (with few exceptions), you are going to be passing through somebody's immigration twice--the last one, the US--unless you are never coming back (which has occured to me). That alone makes it worth the cost.

It may be true you can go to Mexico with your driving license or your birth certificate but WHY? you want to take your original birth certificate?

Please get a Passport, that's is what people use to travel.

If you are just going to TJ, your concern is getting back into the U.S. you won't even be checked on the Mexican side. A valid government photo ID should get you home. If you are planning on traveling further into Mexico, beyond the border zone, I would recommend a passport even though a certified copy of a birth certificate and valid government photo ID will still do it.