As of today, Google Video now allows you to see the hosted videos in a full screen option. Once you click on a video link to view the video, you now notice beside the volume slider that there is a button allowing you to see the video in full screen. If you are currently playing a video, switching to full screen will begin loading the video at the current time within the video.

http://googlevideos.blogspot.com/2005/10/now-with-full-screen.html