This is the live chat box at the bottom of the pages here. You can type a message or two, but then you need to wait a bit. This prevents spamming, using the box as an actual chat client, and stops the people from thinking that they will get a live response. Contrary to popular belief, this is designed for people to post discussions about the page, such as questions about the content or corrections. It is not hooked up to my phone/pager and I don't stare at my computer screen waiting for more people to post messages.
You can download the PHP scripts here: feedback.zip
This is a live copy of the scripts that I am using, including the words that I am filtering (avert thine eyes!) and the rules that I employ. It is designed to go with a theme system, but that section isn't included. So, if you see references to $theme, you now know why that's there.
There is a simple readme.txt file that discusses how to set it up. Really, the documentation for this thing is utter crap, but if you post comments below, I will attend to your issues and try to help work things out.
Server Requirements: PHP 4.x (or so), MySQL