I too had a two year old who expressed himself this way. I had a daughter before him who didn't behave that way so I was sort of surprised and shocked! Then I realized that he had lots of "boy energy" and that sitting around the house was not working for him. I started leaving the house early in the morning and taking him to the park where he could run and climb on play structures and really be physical. Especially when babies this age aren't talking yet, they get really frustrated. You might try teaching him sign language-it works wonders to help them communicate. You can teach him signs for "thankyou" and "please" and "I'm hungry" etc,etc. I don't necessarily think this behavior is a temper tantrum per se, but that he has a lot of energy that needs to get out and he doesn't know what else to do. It really worked for me and I hope it will for you too. Hang in there and remember he really is just a baby and try to see what he's trying to communicate.