When I came here five years ago, I had to learn the "American" word for pretty much everything. Mostly it was something trivial like it's called a "Trash Can" here and not a "Dust Bin."
One phrase that got me a lot of weird looks was "Long Distance." Everytime I wanted to make a Long Distance phone call on someone's phone/cellphone, and asked them about it, they would give me some VERY WEIRD LOOKS! Most just said "WHAT THE #$%#" and went back to doing whatever they were doing.
I remember this one incident back in Jersey when I was on the campus bus and needed to make an urgent Long Distance call to a family member in Texas. I asked the girl sitting next to me if I could borrow her cell and she smiled and said "Sure" as she handed it to me. I politely asked her if she has Long Distance and she said "WHAT THE HELL YOU FREAK?!!!" and snatched back the phone. It was a long bus ride that day.
Of course, I wasn't really using the exact phrase "Long Distance" but another substitute that I thought meant "Long Distance." You see, in India, for "Long Distance" phone calls, we use the term "Subscriber Trunk Dialling," or the acronym STD. Incidentally, STD stands for Sexually Transmitted Disease in US. Oops!
No wonder the girl snatched back her cell when I asked her "Do you have STD?"