Not so much a phrase, but I do a lot of training around the states, and bring my Canadian accent with me. I often get a good natured mocking from whatever group i end up training. The last group was in Atlanta, who kept asking me to say 'Aboot' and 'Eh' ... happens all the time, and actually works pretty well to loosen up a really serious group sometimes.

I also picked up the subulties of Y'all being for one person, and All Y'all for a group of someones, back when I was doing phone support at my last job - i might be one of the few people up here that pop it into conversation. Its just one of those uncommonalities up here, so i usually get laughed at my by friends when i do