I put those feedback boxes on almost every page of cthreepo.com. The code is remarkably simple, which means that it probably breaks easily. Each page has its own data file and comments. I have to watch it for spammers.

Next I need a way to moderate the comments so I can get rid of messages left by flamers and other idiots.

If it works out I’ll put it out for the public to download and put on their own pages.

You can see an example on: Keith Graham's Book Blog.