Hackers?

Every few days I get somebody posting a message to my guestbook -- usually something like "Great site, keep up the good work."

These smell like hackers, but I don't know what they might be up to.

Any ideas?

I visited your site and was unable to locate any guestbook. Anyway what you describe is spam. Automated postings used to spread links for various websites. If you look in the sticky thread there is a link to the thread where I describe a simple method to combat this type of spam.

Thanks! Our guestbook is at http://www.ussrankin.org/guestbook/

I try to delete the spam as soon as it gets posted.

I have visited your guestbook before for some reason. Eludes me right now.

It had been horribly hacked, and you helped unhack it. Then I did a lot of customization with your guidance.