Google Talk chatback badge will let visitors to your web page chat with you. They’ll be able to chat with you whenever you’re signed in to Google Talk.” The badge will display your online status (whether you're available to chat or not) and, optionally, your status message.
What U need in order to create one for your blog?
U need to be an Gtalk user.
If you're not a current Google Talk user, you'll need to create a new Google Account. If you have Gmail on your Google Account, you can use Google Talk with your Gmail account.
Lets Get this one for your blog :
to create read the below details and visit : gtalk badge
Title: Text appearing in blue.
Your nickname: Name Displayed to guest.
Style :click on the drop down list to select to select from 6 options.
Click Update badgeCopy the HTML code From below And paste in your gadget list