Further to the previous, people who call any appointment with someone a "date." To me, a date is romantic. If I go out with friends, it's not a date (unless we're paired off in couples.) If my child goes to play with their friends, they're doing just that, going to play; it's not a "play date." If I have to see my doctor or dentist or lawyer, that's not a "date", unless we're planning to go for a candlelit dinner afterwards! Also very American, and annoys me intensely.
People on forums who just post "Bump" to get a thread back to the top. I don't like "bumping" anyway. It's annoying to see a thread come up again and again because someone is trying to force interest in a subject that people clearly are not interested in discussing (otherwise the thread would already be active)