Some forums require an moderator to review a users first couple posts before they are visible to everyone else to make sure they aren't spam bots. Then the mod activates the users account and the posts become visible. Could we have something like this, rather than letting the bots spam and then deleting their posts?

I know this would be more work for the mod team, I will volunteer to help!

 

...a LOT more work, but since this site lets in everyone it's not a huge deal and it could be a batch job...

There are also Google spiders that pop around automatically as well, which is a good thing as they populate search engines with relevant information. That doesn't tax anything too much.