Google Mail Users Now Have Video Conferencing

Video chatting from Gmail is available now.  Just click on the new "Video & more" menu in a Gmail chat window and select "Start video chat" or "Start voice chat." You can switch to a full screen view or pop out the chat window and change the size and positioning as you wish. 

http://googleblog.blogspot.com/2008/11/talk-face-to-face-right-from-within.html