We've just installed new spam prevent tools on @tilingforum - we already had great control over spam and protection against it; but we've now gone one step further!
There's a new bit of software doing the rounds doug, which actively looks for the major forum software and tries to defeat the registration process just to post spam links. This was one of the main reasons why all registrations are manually approved here. But we now have new tools to prevent the spam registrations too