If you want to view a youtube video in full size, without all the other stuff from youtube surrounding the video, just do the following.
Using this URL about Amazon EC2 as an example:
Just change the URL from the above, to this:
Then you will get the video in full screen mode, without all the other stuff around it.
So all you do is change '/watch?v=
' to '/v/
I found this little trick while messing around with youtube-dl.py script.