QuickChat is a Firefox extension that allows you to chat to people in real time who are viewing the same web page you're viewing. It sits in your status bar, along with the other extensions that are there, and allows you to see if there are any other QuickChat users on any of the web pages that you visit. If there are, and you feel like chatting to them - or at least seeing what they're saying - then you click on it to open up a small frame at the bottom of Firefox that houses the chat window.

I've only been using it for a day, but it seems a pretty cool idea. If you use Firefox you can get it here.