This is something I found on another site. It increses the video quality of some youtube videos. it doesn't work on all for some reason but just type &fmt=18 at the end of the url
before:
http://youtube.com/watch?v=4RpzfVXfL08&feature=related
after:
http://youtube.com/watch?v=4RpzfVXfL08&feature=related&fmt=18
see the difference?
i do see the diffent and i do agree with B.u.S on that