When do I need a passport?

Starting Dec. 31, 2006, skipping around the Western Hemisphere flashing only an official picture ID will be a thing of the past. A new U.S. State Department rule will require Americans to carry their passports when they are traveling by sea or air to/from Canada, Mexico, Central and South America, the Caribbean and Bermuda. The initiative will extend to land travel Dec. 31, 2007. However, such U.S. territories as Puerto Rico and the U.S. Virgin Islands are exempt.

Until the change, the areas in question are Canada, the Caribbean and Mexico.

* Canada: Proof of citizenship is required, including a government- issued birth certificate or certificate of citizenship, as well as supporting documents like a passport or photo ID.

* Caribbean: The following islands require only an original or official birth certificate and a valid driver's license or official picture ID: Anguilla, Antigua, Aruba, the Bahamas, Belize, Bermuda, Bonaire, Curacao, Puerto Rico, Montserrat, St. Maarten/St. Martin, the British and U.S. Virgin Islands, Dominican Republic, Dominica, St. Kitts, Nevis, St. Lucia, St. Vincent and the Grenadines, Granada, Jamaica, Turks and Caicos, and St. Eustatius.

Barbados, Trinidad and Tobago, Martinique, Guyana, Suriname, Haiti, Guadeloupe and St. Barth's do require a passport. For other islands, contact the Caribbean Tourism Organization (212-635-9530, www.doitcaribbean.com) or the tourism office of a specific island.

* Mexico: Though many routinely cross into Tijuana with just a driver's license, the official word from the Mexican consulate is that Americans need a passport to enter the country, whether by land, sea or air.