When I moved to Alabama in 1990, one of the many food-related terms that confused me was the use of the term "Coke" for any kind of carbonated beverage. To me, "Coke" meant Coca-Cola, not orange soda or Diet Dr. Pepper or Mountain Dew.
Now, thanks to the bloggers at Chow.com, I've discovered a map that illustrates this phenomenon -- as well as the fact that when I traveled to Colorado in sixth grade and tried to order a "soda" in Kansas, what I got was an ice cream soda!http://strangemaps.wordpress.com/2008/08/18/308-the-pop-vs-soda-map/
(If you'll note the little island of "soda" users in the middle of the country, that's where I grew up.)
Another time I'll talk about what I thought of terms like "creamed potatoes," "fried corn," and "field peas with snaps"...