This is a fun topic. I grew up near Philadelphia and now live in BC. The "philly" accent is pretty distinct (think
Rocky), so a lot of people notice it around here. Often, people ask if I'm an American, so there's something.
One of the things I've noticed, since I'm also an elementary school teacher, is that the ZEE/ZED thing is not necessarily happening any longer. Canadian teachers attempt to teach "zed", but that is losing out to the "zee". Mostly because of the singing/rhyming aspect. There's actually a Canadian version of the alphabet song that I don't recall, but it makes the "zed" a rhyme.
The "eh?" is a good give away for a Canadian. Many Canadians use it unconciously. My Canadian wife uses it, but will deny it to others unless I'm there to point it out.
Another pronounciation that I've noticed around here is the word "often". The "t" is pronounced here. Americans tend to keep it silent.
These words "mazda", "drama" and "pasta" are pronounced with two short "a" sounds instead of the America schwa sound. Some people actually say "President O-BAM-A" here. I jokingly threaten to call there country "Ca-NAY-DA" if they keep it up.
Teacher went on too long...sorry. I'll just close with a fun link to the online Canadian Spelling Dictionary that I find informative and used a lot when I first moved here..
http://www.luther.ca/~dave7cnv/cdnspelling/cdnspelling.html