Comment spammer out of control

Can someone help?

Some guy has been spamming my site for 2 days now, the comments wont stop coming. I have tried adding the words into the blacklist section of the comment discussion options but nothing is working, for some reason they are still getting through.

They are at least getting caught in the moderation queue, but I am getting about 10 an hour and it’s really starting to get to me.

How can I just turn commenting off for a while? I tried clicking that “Allow discussion” option thing off but the comments are still coming in.

What can I do?

I have Askimet installed but this seems to be something new so it’s not being captured.