Once you have a guestbook and the facility to post messages to it you'll also want to be able to display the messages and this function goes most of the way towards that by fetching all the messages from the datafile and returning them in an array. It does this rather than display them directly to leave you in complete control over how you want the output to appear.

The Figure shows posts from a Guestbook simply being displayed as regular text with no special formatting.

Using this plug-in it's easy to list all your guestbook posts