You need yours also; otherwise he will be able to come back; you won't.
You don't need a passport if you are coming back from Tijuana, I asked the immigration people and they said it's fine with the ID and Birth Certificate. Actually if you go walking there are 2 lines one for passport and the other one is for people that don't carry passport.
If you have an ID and birth certificate, you shouldn't have any problem re-entering the US.
Yes.
Yes you do.
If you are already in Mexico, sure you can.
No. You cannot use a US birth certificate to cross the US/Mexican border in either direction. US citizens may use a passport (booklet mandatory for air travel), US passport card, "enhanced" drivers license or "enhanced" non-drivers ID.
Yes, but you will not be able to reenter the US without a valid passport. (source below)
You need an American ID, birth certificate or US passport. Note you don't need anything to cross into Mexico; however you will need any one of these documents to return to the United States.
Yes, the three of you will need a passport.
U.S. citizens do not need a passport to enter Mexico by land or sea. The Mexican officials at the border do not ask for any identification from you. On your return home, the U.S. officials would like you to carry a current passport but they can't obligate you to do so. Every day hundreds of people cross from Tijuana to San Diego with only a driver's license. See related links section.
Yes, passports are required on flights between most countries these days.
I'm on felony probation. I was on parole before and I applied for a passport and received it 5 weeks later. I don't know if you'll get detained by customs on your way back. I haven't used my passport yet. At least now you know that you can get a passport if you're on probation or parole.