An instant messaging hyperlink is a link that a person can click on that will instantly open the correct chat window with the person’s chat ID already in place.
Here are the chat hyperlinks for some populer instant messaging networks. Just enter your username where it says USERNAME and then copy and paste the whole bold line into your website / forum / chat signature, whatever.
Windows Live Messenger :
(the username in this case being the Hotmail address)
Yahoo Messenger :
Google Talk :
(the username in this case being the Gmail address)