I know a good way to stop spam. I think we should have to wait exactly one hour, between signups. I can't think of any reasons to make two accounts at the same time other than spam. I think this will reduce spam.
I don't really think this will stop them, I mean if they really plan on doing some major spam they'd have created 5-8 new emails before and create the accounts when their latest got banned...at least I think that's how it works. I would rather have a IP-based limit, which can only be lifted by an admin or something. It'd be much more effective, until they use proxies o.o
