When my son started the whole tantrum thing, I would just tell him I'm not interested in listening. I would tell him to go to his room and have the tantrum, or sometimes, I would carry him in there and put him on the floor and close the door. All very business-like and matter of fact, no raising of voices or anything. I just made him understand that he could tantrum if he liked, I just wasn't interested in hearing or seeing it. LOL....When he realized he wasn't doing it for anyones *benefit*, he realized it was a waste of energy. I know this doesn't help when you are in public, but by doing this we never had a tantrum in public.