Actually, I'm ashamed to admit, but my son, boyfried and I all use that word occasionally, just goofing around. If one of us trips or drops something or says something stupid, the other one might say, "Way to go, retard." It's meant totally as a joke, just poking a little fun at each other. I honestly never thought about it before, and certainly never made any conscious connection to handicapped people. We just say it like we would say, "Goof" or "Wierdo" or "Silly". I guess we'll have to be more careful not to say that.