I've tried a variety of guestbook scripts, but none of them were quite what I was looking for. They were either too hard to use, or too insecure, or just didn't work well with the rest of my site. So I did the same thing that I did when I was looking for a blog: I made my own.
Vanilla Guestbook aims to be to guestbooks what VSNS Lemon is to blogs. It should be simple and functional; easy to set up and use, but full of features that you'd expect in any script. It is not designed to be an awesome, one-size-fits-all guestbook. Rather, it is designed for both the casual and experienced user who want something simple. You can even use it as the launching pad for your own guestbook script!
Version 1.2 is the first stable release of Vanilla Guestbook. While it comes with a few new features, the main focus was on fixing extant bugs and correcting security holes from previous versions.
Vanilla Guestbook requires PHP 4+ and MySQL 4+ in order to work.
There's no documentation for Vanilla Guestbook at this time. Depending on how much of a priority I give to developing it will also affect how much priority I give to documenting it.