I'm working on a swf compiler, and actionscript bytecodes have become my life recently. Even if you could care less, you might like this... If you want to insert bytecode in your flash file, you can use __bytecode__("hex vals");. Someone from mm had mentioned that at one point in passing, but I hadn't tried it till a few days ago. I put an quick bytecode extractor on the compiler, and it works great. So you can easily inject those special loops (that are built for speed not for comfort) right into your work. And work it does, like a champ. Example? Paste this into Flash (watch for wrap):

__bytecode__("88240002006900486F6C7920736869742C2062797465636F646520696E2074686520666C612100960B0008000600000000000000003C96020008001C960500070A00000048129D02001500960200080126960400080008001C501D990200D6FF00");

Maybe this is old news, but I will certainly put a pcode mode in the compiler knowing that. In the meantime, flasm is your friend : ).