Blog have also fallen prey to spammers. So-called "comment spam" are responses from automated robots that link to commercial Web sites and have no relevance to the blog post. Most spammers don't even care if users click on the links but are creating them to improve their own search engine optimization. Here are some thing that I read that you can do that can help.

1. Require a login. If you don't have the time to pore through all of the comments before users post them, requiring users to sign in can reduce blog spam.

2. CAPTCHA (complete automated public turing test to tell computers and human parts). When a site asks you to type in a certain word, it is trying to verify that there is a person on the other end, rather than an automated spammer. A free solution is available at www.reCAPTCHA.com

3. Software Filter. Akismet (www.akismet.com) is an automated service similar to Postini but for blog commenting systems.