http://www.digitaljournal.com/article/265783

YouTube introduces videos in Gmail chat window

Posted Jan 23, 2009 by Chris V. Thangham
In Gmail chat, we can now exchange videos link with one another and see them in the chat window itself. It is not necessary to open a new page.
See YouTube videos in Gmail Chat
See YouTube videos in Gmail Chat
Gmailblog.blogspot.com
Once you have enabled the chat in your Settings page in Gmail, you can now see YouTube videos within the chat window. Google shows a preview of the YouTube video in chat.
Without this new feature, you have to open the link in a new window, which disturbs your current chat conversations with friends.
An example of the chat conversation is shown below:
See YouTube videos in Gmail Chat
See YouTube videos in Gmail Chat
Gmailblog.blogspot.com
The YouTube video appears in a small screen, so when you click the “play” icon, you can watch the video while you chat.
This YouTube preview is available only within Gmail platform, it is not available in Google Talk chat platform. It is not clear why it is not available in the main Google Talk platform.