You may not need a Plan B ...
If you plan to fly to Canada, then yes, a passport is needed.
BUT ...
If you're driving to Canada, then a valid drivers license with photo and birth certificate are all you need for now - this changes on June 1 '09 when you'll need a passport (the same goes for Canadians traveling to the USA).
The following is from the U.S. Department of State travel site for Canada (as of Feb. 17, 2009)
http://travel.state.gov/travel...tw/cis/cis_1082.html ENTRY/EXIT REQUIREMENTS: Entry into Canada is solely determined by Canadian Border Services Agency (CBSA) officials in accordance with Canadian law .
Canadian law requires that all persons entering Canada carry both proof of citizenship and proof of identity. A valid U.S. passport, passport card or NEXUS card (see below) satisfies these requirements for U.S. citizens. If U.S. citizen travelers to Canada do not have a passport, passport card or approved alternate document such as a NEXUS card, they must
show a government-issued photo ID (e.g. Driver’s License) and proof of U.S. citizenship such as a U.S. birth certificate, naturalization certificate, or expired U.S. passport. Children under sixteen need only present proof of U.S. citizenship. It is very important to note that all Americans traveling to the U.S. by air, including from Canada, must present a valid U.S. passport to enter or re-enter the U.S. Effective June 1, 2009, a similar requirement goes into effect for entry into the U.S. via land and sea borders. All Americans will need to present a U.S. passport, passport card, NEXUS card, Enhanced Drivers License or other Western Hemisphere Travel Initiative (WHTI)-compliant document in order to enter the U.S. by land or sea. American travelers are urged to obtain WHTI-compliant documents before entering Canada well in advance of their planned travel. For the most recent information on WHTI and WHTI-compliant documents , please see our web site.
The following site is a bit more succinct ...
http://travel.state.gov/travel/cbpmc/cbpmc_2223.htmlCheers!