Thanks Playfelt. I am thinking of making a quiet corner for him by moving some furniture or something. I have been watching him like a hawk and he had three time-outs this morning...after that he calmed down a fair amount and played with much less aggression. I will definitely think about an area where I can block off with furniture or gate off and let him play there when I can;t be right beside him. Maybe he'll get the point if he suddenly has to play alone. His language skills are quite good, so I know he understands (at least on the surface) that he shouldn't push, hit etc. He just doesn't control his impulses.