K.M.
Is he only doing this in public places? I'm not at that point yet, my son is only 4 months old but what worked w/us when we were little was my mom and dad set rules before we left the house and then stated them again when we got to the store. If we acted up or threw a tantrum we were leaving, didn't matter if there was a cartfull of groceries or in the middle of dinner, we acted up, we left. They only had to do it a couple of times before we realized they meant business. (plus when we got home, there was no toys or t.v.) at home. Good luck!