I know you can flag posts now. But why not threads? Say after [x] number of flags a thread get's added to a Mod's [list] to be reviewed, and deleted if nessesary.
I heard from some mod if a thread is full of spam, or is inappropriate, just flag the first post. It's the same as flagging a thread as it draws attention to it.
An OP isn't any more special than regular replies, but if it looks like an opening to a thread and it looks like trouble, then a mod may lock/delete it if enough users flag it.
I like the flagging thread idea, this could go into a different category in the mods inbox or whatnot and make it much easier to delete spam threads before the explode.