I've been using credit cards in the US for almost a decade now. I'm familiar with cash back cards, mileage cards, and why some people refuse to use cards. But that's not why you rang — we're not here for the pros or cons of what amounts to a personal decision. We're here to find out how credit cards are slightly different in Canada than the US.
The Smart Card
Oh sure, your US-based credit card will swipe just fine at most every store in the Greater Toronto Area, but you'll be about the only person around swiping a card. Most cards here have a smart card on them for the Interac network, and instead of being swiped, they're inserted into the bottom of the machine.
The Transaction Is Yours
For years I've heard fears voiced at restaurants when a server takes a credit card to the register that "You just don't know what he or she is doing with it!" Apparently having the same distrust, but acting upon it, servers typically bring the terminal to you. Comically, the terminal comes to you in drive thrus as well, right out into the elements on a long cord.