That is my word. Well...that, "whatever" and the phrase, "oh my goodness."
Said correctly, it can convey sarcasm, dismay, disbelief, a sense of moral and ethical superiority and gentle chastising punishment all at once. Seriously.
The characters on my new favorite show, Grey's Anatomy, also love this word. They use it left and right. One night while I was watching my show, Bertrand overheard part of it and said, "hey, they talk like you." I know! These are my people.