Dear users,
As many of you will have noticed, there has been a large increase in the amount of spam on BCUK of late. In order to protect our community from these attacks, we have decided that as of early next week, it will temporarily not be possible to register new accounts on blog.co.uk.
This will cut down on spam drastically while we implement some changes that we believe will continue to keep spam to a minimum. Naturally, general performance will also improve as we delete the mountains of spam that have been building up recently.
The block is likely to remain in place for several days, so if you or anyone you know is thinking about registering on blog.co.uk, please do it before the weekend.
We apologise for the temporary inconvenience that this will cause, however we are convinced that the improvements that will result will hugely benefit the community as a whole.
Thanks for your understanding,
your BCUK team
ajnspencer
Pro 
This might be a totally unworkable idea but have you thought of doing what other sites have done against spam and have community moderators?
Site members who've been around for a while and whose only "extra" would be the ability to blacklist a blog, making it impossible for anyone to post on it until a member of the team had checked the decision, perhaps even "close" the blog shortly.
If it was a power solely to be used for "spam" it should be obvious to the moderators who to block and as it's not as final as deletion it wont be critical if the moderator errs on the side of caution wrongly.
It'd also be easy to maintain a level of service for the moderators as if they show bad judgement the ability could be revoked and a different moderator found. I'd like to think anyone who wanted to stop spam wouldn't be the sort of person to abuse the position.
I know the flagging system works well but I also know your team is stretched thin across the world of BCUK so this would stop a lot of spam at source before it could push too much Googlebombing through the net in the time between flagging and the support team being able to take a look.
I think the general level of hatred for spammers around here should mean it would be a popular idea.