Mindy, to go back a few pages and clarify something:
I've lived here five years, and have been a freelance editor for American clients, exclusively, in that time. So I write and edit the American way, and given that I work at home, more often speak to Americans over the phone than Brits face to face. Some Brit terms have become part of my normal speech (for example, "take the piss/taking the piss"), be it with Brits or Americans. But thank you, balmer and hopster, for saying it's okay to be true to your normal speech. My mother-in-law (a lover of language, as am I) play Scrabble and other word games, with the only rule being that words and spellings from both British and American English are allowed.
Of course, when in Rome, do as the Romans do. So, as I said, if speaking to Brits, you should use British terminology. But I think it's pretentious to speak to other Americans with words that trip off your tongue. That's why people take the piss out of Madonna and Gillian Anderson--"I live in England--SUDDENLY I have a British accent."
And, on a different note, I've heard Anne Robinson mispronounce Spanish words dozens of times on "The Weakest Link," and have the nerve to correct people who pronounce them correctly (contestant pronounces "Jose" appropriately--ho-zay; Anne Robinson cuts on her and says, "It's JO-zay"). Neither Mexicans NOR Spaniards pronounce it that way, just as filet IS pronounced "fill-ay," regardless of how it's spelled. It's a matter of knowing basic pronunciation rules of other languages...