The big thing for me whilst shopping in Orlando was when I asked for a medium. I pronounce it "mee-jum" in a broad Glaswegian accent. You guys say "mee-dee-um" - probably as it is supposed to be pronounced and it became my "new word" for the whole 2 weeks!

One addition to Alex's:
city centre = downtown
Most people on the East of Scotland call the city centre "uptown". Imagine a conversation between an Edinburger and a New Yorker about city planning!