Guestbook plugin

Is there realy no one out there that have build or know about a guestbook plugin?

If someone could make one they would have a ton of sales, i for one am seeing a huge demand from clienst to have a guestbook on their website, that dosent require them to log in and enables them to add images, in a way that limits spamming.

I realy need help with this as im unable to find one that have the features and realy works.