Chat With Your Site's Visitors Using Google Talk:
Google Talk's gadget was a nice addition, but you couldn't use it to chat with unknown people or with the visitors of the site, like in Meebo Me. Now you can do that using the new chatback badges. You only need to add some code to your site and anyone could click on the generated badge to chat with you.
"A Google Talk chatback badge allows others to chat with you even if they haven't signed up for Google Talk or a Google Account. You can put the badge in your blog or website, and people who visit those pages can chat with you. The badge will display your online status (whether you're available to chat or not) and, optionally, your status message."
If someone clicks on the badge, a special version of the Google Talk gadget will open and he will be able to chat with you.
The conversations are private and only one-to-one, so other visitors won't be able to read them. For some strange reason, they're not even added in Gmail's chat section. Unfortunately, being constantly interrupted by other people is not very pleasant, so you can disable the link from your badge by setting your status to "busy" or by signing out of Google Talk.