I just finished reading the latest issue of LinuxJournal (the blog special that I mentioned earlier), and it had some very interesting articles. There was one main article about blogs, and the options out there for blogging systems in general, and listed some referrer sites, as well as how Google seems to promote blogs in their listings, an interesting read. Also they had a few articles about fighting spam by using Bayesian statistical methods to determine from words if the email was spam or not, and went into detail about the formulas used to make it all work. I highly recommend this issue to check it out.
Innerdimension.net