My DS bangs his head on the floor sometimes too. If he throws a tanty I pick him up and put him in the playroom and walk away. I don't want him to bang his head on the tiles in the kitchen or the floor boards but if he wants to bang his head on the carpet then that's his thing. It only lasts for a few seconds and he realises he's not getting the attention he's after and stops. He's never had a full blown screaming fit though - I'm sure that's all to come!