We want to remind you that starting January 31, 2008 when re-entering the United States from Mexico by foot, motor vehicle or other type of ground transportation you need the following:* Proof of Citizenship: Passport or Birth Certificate AND * Proof of Identity: Government Picture ID like a Driver's LicenseThis requirement is already in effect for air and cruise travel.Children under 18 are only required to have:* Proof of Citizenship: Birth Certificate (when traveling with their parents.)Please reference the following government websites for more detailed information: http://www.getapassportnow.com/