I grew up in the edge of the Chicago suburbs. I always felt like my accent was "neutral", ie, I didn't have one (but maybe everyone feels that way). At age 22 I moved to North Carolina, and I realized I did have an accent. I've lived here for 13 years now and I feel like I sound like all the other non-natives. I have grown to love the mid-southern accent, and I find myself using it in casual communications such as speaking to the cashier at the grocery store. I also like to say "y'all" but I'm guessing that to a native I still sound like a yankee. I guess at this point I have a bit of a hodgepodge. My family tells me my accent has changed when I visit them but I only notice it occasionally when I speak to people from here (and in my town most people are transplants from all over and sound "neutral" to me).
Certainly I sound very American. I was just wondering, how much do people from other countries differentiate various areas of American? To me they differ greatly. The most different from from anywhere else is the northeast ("New England") states. My drummer in my band is from Rhode Island and he sounds pretty neutral except for some words, and when he wants to accentuate his accent, which I find hilarious and which he basically only does for the sake of being funny. There are also some funny midwest words... for example, the word "wash" is pronounced like "warsh" in some places.