I loved your design and will suggest my friends to visit it aswell. I have created Banner-exchange of my own if you like to share it for others. Chatters actually can see each other.
Users can alter their look in the chat, construct their own chat-rooms and invite guests.
They also have FREE email and FriendFinder. Your site is good. But you've made this immense tower of logic look a little bit more understandable. You assume all risks associated with the using theGuestbook.