New Passport Rules

We're less than a week away from the U.S. Department of State's implementation of the last phase of the Western Hemisphere Travel Initiative. As of June 1, 2009, travelers returning to the U.S. from Canada, Mexico, Bermuda or the Caribbean region by land or sea will need to show a passport or passport card. Certain groups of travelers, such as Native Americans, will be allowed to show other approved documents.
If you've put off applying for your U.S. passport and plan to take a cruise or drive across an international border in the near future, it's time to find your proofs of citizenship and make an appointment at your local passport office. The Department of State reports that passport applications currently take four to six weeks to process; expedited service is available - for $60 - if you need your passport in two to three weeks.
 
http://seniortravel.about.com/b/2009/05/25/new-us-passport-regulations-take-effect-june-1.htm