Enter: "The Terrible Twos"

Grant is not quite 2 yet (he will be in January) and already he has adopted that infamous expression, "The Terrible Twos." I was hoping that he would just bypass this all together, as his sister and brother (but mostly sister) gave me more than my share of tantrums and general mischievousness. However, it has hit, and early. The other two waited until about 2 1/2, and it lasted about a year each. Now, they are mostly gems, except when they are fighting with each other over a toy or that dang swing we decided to put up in the backyard (yay for cold weather in that case).
But Grant, well....He is just dang mischievous! I think some days that he is just getting the other two back for whatever they did to him when he was more helpless. He swoops down on them like a bird of prey before I can even react. For example, he was meandering through the living room, putting things in this metal wine bucket I have on the floor for decoration and to put ashes in from the fire place when needed. It is clean right now, and he often plays with it, as the other two did. He sauntered over to where Rogan was sitting ever so casually, and the next thing I know, he throws it at Rogan's back full force. Rogan screams, I jump and don't even know what to do. He just smiles at me when I reprimand him, slap his hand, or put him in a chair for time out. How do you discipline a two year-old? I still haven't figured that one out. Whenever I say "No! No!" or "Naughty" he thinks it is funny and shakes his finger at me saying "NOT-TEEE!" The other day, Doug was leaving and he says, "Bye Bye, NOT-TEE!"
All day long, I got through constant attempts at reprimands after he throws things at each of us like metal water bottles full of water, remotes, pens, books, etc., pulls big wads of hair out of the kids, and me one day, and throws his food on the floor laughing. The worst part is that, the other two seem to encourage him, especially when he throws his food, by laughing. Then they all get in trouble.
It isn't that he isn't getting attention either, because he will do it in the middle of me playing with him, or the others playing with him.
UHHHH!!!! I hope this phase is short-lived. He really is a sweet baby, but this streak is so frustrating!