Knotty, deleting pingomatic or any sites to ping from the Update Services field means that you blog will never send out notification to the popular blog update services. Many people subscribe to these services to receive an email notifying them of which blogs were updated that day. This is widely used by individuals who are too busy to watch RSS feeds all day. Unfortunately, bots also watch these update services and attack blogs as soon as they post. Disabling your update services will get rid of a lot of SPAM bots, but it will also alienate a lot of readers. I prefer to keep this and IP blocking as last resorts. Why keep IP blocking as a last resort? Because unless the IP list is continually maintained, you may end up blocking future or current readers as well. Rarely do spammers ever keep a unique IP, and if they do, they don’t keep it for more than a week. Usually, the spammer’s IP address will be dealt out to another “innocent” client the next week. One day, that could be you and you’d never be able to change it or fix anything until you receive a new IP (imagine how your readers would feel if that happened to them…a loyal reader suddenly blocked). An IP address block should only be used to stop a SPAM flood, and then deleted after 24 hours. Really, the best way (if you don’t mind giving control over to something other than yourself) is to use WPBlacklist to delete entries posted with a specific URL. Yes, this isn’t a 100% end-all cure. The spammer could always buy a new domain name, but at least he has to pay more money for it.