A couple of points on this:
- All that is currently required for entrance to the US is an original birth certificate (no photocopies) and government-issued photo ID (like a driver's license).
- Having said that, the US government can decide at any point to require a passport from Canadians. They can do this without warning and lead time. So if they decide on Monday that you need a passport, you need a passport. Period, end of story, thanks for playing. No amount of complaining will help.
- If you have time to get a passport, do it. They cost $85 and a little bit of time from your day, and are good for 5 years. That's $17 a year, or $1.42 a month. That's less than getting a Tim Horton's coffee a month! They need roughly 10 working days to issue a passport, although you can pay a fee (I think it's currenlty $15) to have it expedited.
- SKFamily, whoever told you to take the SIN and health cards was wrong. SIN cards are NOT acceptable as proof of citizenship, as you can simply be a resident of Canada have a SIN card. My fiance is an American living in Canada, he has a SIN and a provincial health card. All those do is prove residency, not citizenship and as such cannot be used for ID. Well the health card can if it has your picture and is used as the photo ID along with a birth certificate (if you don't have a driver's license).
- On the subject of landed immigrants (those residing in Canada but not Canadian citizens) - especially Americans - yes it's true that they don't need a passport to enter the US (for the Americans). They can't get a Canadian passport anyway, since they're not citizens of Canada. BUT they do require the Permanent Resident Card to re-enter Canada if they're travelling by commercial carrier. Without it they can be denied into the country, even though they live here.
Information on the Permanent Resident Card can be found at
http://www.cic.gc.ca/english/applications/prcard.html