Travel to the U.S. from some of our nearest neighbors has become a more formal affair. Since January, air travelers of all nationalities — including U.S. residents — who enter the U.S. from Canada, Mexico, Central and South America, Bermuda and the Caribbean were required to have a passport. Travel from U.S. territories, such as Puerto Rico and the U.S. Virgin Islands, isn't affected.

Previously, you often needed only a driver's license and birth certificate to come home after basking in the sun or schussing the slopes. You'll soon be obliged to carry a passport for sea and land travel, too, probably starting in 2008. New requirements were mandated by Congress in 2004, but the effective date for air travel was pushed back to avoid the holiday rush.

Although initially the change could mean more hassles for travelers, it also means that U.S. Customs and Border Protection officers will no longer have to recognize as many forms of identification. "We hope that over time this will actually speed up the entry process," says Rick Webster, of the Travel Business Roundtable.

In late 2006, passport applications were running about 275,000 per week, twice as many as a year earlier. Getting a new document can take six weeks (and up to eight weeks during peak travel seasons), so don't delay if you're planning a trip. You'll pay $97 to get a new passport, which is good for 10 years, or $67 to renew your old one (the fee is $82 for children under 16, but the passport is valid for just five years).

In a hurry? You can pay an extra $60 and cut the wait to two weeks. If you need to travel in less than two weeks and have proof of your travel dates, you can apply at one of 14 by-appointment passport agencies open to the public. To find a Passport Acceptance Facility (typically a post office, library or courthouse), search by ZIP code at www.travel.state.gov, which also has applications and information on exceptions to the new rules.

For travelers who make frequent trips by land or sea between the U.S. and Canada, Mexico, the Caribbean and Bermuda, the State Department has proposed a passport card that fits in a wallet and would cost $45.