Starting this summer, Americans will need passports to travel to Canada, Mexico, Bermuda, and the Caribbean--unless they have passport cards or one of the enhanced driver's licenses that the states of Washington and New York have begun to issue.

Valid only for trips by land and sea, these new forms of identification are a convenient, inexpensive option for people who don't need to travel by plane. U.S. passport cards, which were introduced in July, cost about half as much as a full passport, and the extra cost of getting an enhanced driver's license rather than a regular one is even lower. Enhanced licenses have been available in Washington since January 2008 and in New York since September; other border states, including Michi­gan, Vermont, and Arizona, intend to offer them as well.