N.,
I have another opinion about time-outs completely. Time out is actually best used as a way to teach your son how to control himself. That means showing him that it's actually a GOOD thing to leave the situation and be by himself for a minute. Making it an unpleasant punishment shows him that it's something that stinks. So here's my suggestion- when he is angry, hitting, hurtful in any way, look him in the eye, tell him that you can see he is angry (this helps him identify that crazy feeling he has inside), and sometimes that's all it takes to stop a child in his tracks!) and maybe needs a minute to cool off, and help him find a safe, soothing place to do it in. You know how you feel better and less stressed after a hot bath? It's the same effect you're going for. Bring him to his time out spot (give it a fun name..., blanket, teddy bear, etc.), let him know that he can stay there until he's feeling calmer, and stay with him the first couple of times so he knows that you are there for him in his state of confusion(imagine not really knowing what anger and frustration is- just feeling it intensely for the first time!).
As for the throwing- WHY is he throwing? If he's frustrated, see above. If it's just fun, give him something safe to throw, and tell him "It's not safe to throw that. We can throw scarves." This tells him what he CAN do, not just what he can't. If it's to get a rise out of you, stay calm, and simply say "If you're going to throw that toy, I'll have to put it away until you're ready to be safe with it." then do it. Return the toy in a couple of days and tell him that he can have it if he's safe with it.
The pretending to cry advice is also great! Children are still learning about their bodies- where does mine end and yours begin? They have no idea how hard they can hit or bite, or that it hurts you or others. Crying shows him that it hurts and begins to build empathy- the ability to relate to how someone else is feeling. Have him help you get an ice pack or bandaid to help you feel better as well.
good luck!