Some related posts from Technorati and Google.

 [Golem.ph.utexas.edu] Blogspam Update | Musings: Perl is very fast crunching through Regular Expressions, but it seem to me that the blog owner is still the one holding the short end of the computational stick. I’ll keep looking at it, though…

 [Jacobsen.no] MT 2.6 Feature suggestion: Collaborative spam-blocking (Anders ...: I'd be concerned about some bloggers blocking IPs of users they simply don't like rather than blocking legitimate cases of spam or harassment. Plonking someone for having a different opinion does unfortunately happen and if, in your example, three or more people don't like what John Doe has to say, he'd be easily added to the banned list by way of pinging a central archive.

[Askdavetaylor.com] "What does this blogspam comment mean?" from the Ask Dave Taylor ...: I was puzzled by this too, I have to admit, until I did a bit of research and found a very plausible theory on the Movable Type discussion boards: these spam messages are really an advanced party, as it were, they're creating inbound links to an as-yet non-existent site, with the thought that their comments are less likely to be removed if they're not pointing to something offensive. Wait a few weeks, build up some inbound links on Google, and then when they do actually launch a site, blammo!

 [Weblogtoolscollection.com] Weblog Tools Collection » WordPress comment spam stoppage techniques: As a response to the many recent articles written about comment spam in blogs and their prevention methods, I thought it would be useful to list all of the existing methods available for WordPress (both in the core and as plugins and hacks) to prevent spammers from targeting your blog and succeeding. I would appreciate it if WordPress users would report their successes and failures with the various methods.

Reflected tags on Technorati: Blog, Blogspam, Targeting Spam