• Powerful spam fighting controls
  • Use Captcha or Saptcha to prevent automated posting
  • Each guestbook generates a unique form
  • Time delay before guests can post
  • Time limit on how long a guest has to post
  • Moderate entries before they appear in your guestbook
  • Block or moderate posts containing bad words
  • Ban ips or even ip blocks from posting
  • Block posts containing to many urls
  • Check guests headers for known spam headers
  • Check a posters IP address against a database of known spammers
  
  
• Apart from their name and their message your guests can tell you their...
  • Email address. You can even make email addresses required
  • Location
  • Website
  • Yahoo! messenger id
  • Live (MSN) id
  • AIM id
  • ICQ uin
  • Skype id
  • Even their gender
  • And guests can upload an image with their posts
  
  
• Other features
  • Powerful AGCode for formatting entries or even displaying pictures and Flash
  • Allow HTML in entries but control which tags can be used
  • Send emails using SMTP instead of sendmail
  • Create thumbnails for images that have a large file size
  • Automatic resizing of images and Flash files displayed in entries
  • Graphical smileys (emoticons)
  • Previewing of entries
  • Other guests can comment on existing entries
  • Email notification of new entries and comments
  • Thank you email sent to guests after posting new entry
  • Search function
  • Email address encryption to prevent the addresses being harvested by spammers
  • Flood controls to prevent people from flooding your guestbook with entries

And best of all every feature listed here is optional and can be enabled/disabled from the admin area