I apologize if this was already posted, but I thought some of you would find this fun (especially if you've never set foot in the US :).
How Y’all, Youse and You Guys Talk
Interesting results, apparently I am a New Yorker despite living in Virginia.
For the record, i do not have a southern accent, but I do say "y'all". It is a useful way to refer to a group of people casually. In truth, I am trying to get out of the habit, not because I think that there is a problem with it, but because I have heard other people who also do not have southern accents use it and it struck me as sounding kind of odd.
I often find myself saying "you guys" even when addressing a group of women, a habit that I'm also trying to get out of.