Here's what we do:
Each new forum registrant must be approved for participation. This weeds out folks with obvious website or e-mail addresses, like BigJohnXXX@smackdown.ru. (25-50 folks attempt to register each day; each one gets reviewd. The ambiguous ones get a pass - which is why we get any spoof-spam at all.)
I receive notice and content of every post for each forum that I moderate, and delete the obvious Paris Hilton postings immediately. (There are 25 or more postings each week day, often more on weekends, mostly at night.)
Then I delete the user account for the 'person' authoring the offening post.
Finally, I add the poster's domain and IP address to my ban lists.
Unfortunately for us all, this only reduces the roaring tide to a freshet.
You can help, by continuing to bring offending posts to my attention (Jim Rogers is the absolute champion at this!). I will remain vigilant.
PS, I do NOT do this work when I am travelling, because it is just all too tedious to accomplish from the Blackberry. So I do skip at least a couple of days a week, sometimes catching up from the hotel, sometimes letting it all slide for a day or two.
