The legal requirement for crossing the border in either direction between US and Canada is to unambiguously establish your citizenship (US or Canadian). To enter the USA others may require additional paperwork, e.g. Visa Waiver form I-94W or a visa stamped in the Passport + form I94). To establish US citizenship any one of the following is sufficient:I'll get a passport (had one a long time ago -- expired). That and my driver's license and my retired Navy ID card SHOULD be enough for anywhere! Thanks guys.
1. US Passport (has a photo on it and you need either a Birth Certificate or a Naturalization Certificate to get your first one)
2. Birth Certificate establishing birth in USA or of US citizen parents + govt issued photo id (e.g. Drivers License)
3. US Naturalization Cetificate (has a photo on it)
Personally, I carry my current valid Passport all the time when I travel. The color of my skin and the country of my birth makes it imparative that I carry squeaky clean credentials establishing my citizenship, so no trying out expired Passports for me . If you have a Passport, a Drivers License does not add anything. Afterall one does not have to be a citizen to have a Drivers License.
And BTW, I would be very happy with Montreal too. I have personally covered less of the Toronto system than the Montreal system, thats why I voted for Toronto.
Jishnu.