The only thing that stands between you and the nicest guestbook program on the Web is one line of code, and $123.89 a year.
TALQO Guestbook by Webanautics is a hosted guestbook solution for your website. WYSIWYG editor for your guests, customizable tags and events, and unlimited photo and movie hosting. Guestbook visitors can upload up to five (5) photos and/or movies. These are searchable on Flickr (a Yahoo product) by event tags which you, the site owner, create. This means more search results lead to more visits to your website, as more guestbook visitors leave more photos on your guestbook.
Get your own one line of code to rule them all here