New passport rules for international air travelers are in effect as of today (Jan. 23, 2007). Beginning today, all persons traveling by air from Canada, Mexico, the Caribbean, and Bermuda -- including U.S. citizens -- will be required to have a valid passport in order to enter the United States. Learn about the New Passport Law from FindLaw. If you need a passport, the U.S. State Department has helpful information for First Time Passport Applicants.