Chatsum is a FREE add-on for your web browser that lets you chat with all the other Chatsum users that are looking at the same website as you.
It is basically a browser extension with which you can chat with users who has chatsum extention on their browser.Its been few days since I applied for a beta account there, hope they allow me to use chatsum soon :) .

Chatsum lets you:

  • Chat live with other people who are looking at the same website as you!
  • Find out what other people think about the websites you’re looking at!
  • Leave messages on any website you visit!
  • Read messages left on websites by other Chatsum users!
  • Browse the Chatsum community’s favourite websites!
  • Hunt for treasure in our unique online treasure hunts!
  • Find people that like the same sites as you and then CHAT TO THEM!