I’d say no, unless you’re going by boat.
The same thing, with the vague and confusing “other valid travel document” part removed.
http://travelwithkids.about.com/od/insurancedocuments/a/passports.htm
What’s changed about Passport Requirements?
Before January 2007, US citizens were able to travel to Canada, Mexico, and many countries in the Caribbean without needing passports. Birth certificates and photo id were sufficient.Passport ID is now required, as part of a “Western Hemisphere Travel Initiative” that the US is implementing for border security. (Read more at the US State Dept. site.)
The first phase of new passport requirements began January 23 2007, for air travel: all US citizens – adults and kids–need passports for air travel to and from the Caribbean, Bermuda, Panama, Mexico and Canada, in order to enter or re-enter the US.
Arrivals by sea: cruise passengers, meanwhile, have a different date; passports won’t be required until June 1 2009, for those crossing borders by sea.