Download html5 movies from youtube
NB: Due to a change in Youtube this stylesheet unfortunately no longer works
Normally videos embedded in html5's <video> tag can be easily downloaded with Opera by right-clicking on the video and selecting "save video" (like here), the .webm, or .ogg, file can then be saved to anywhere on your PC. Youtube tries to prevent people from doing this on their site by placing a blocking element over their videos. This simple .css file removes that element, restoring the normal right-click menu to the user, and letting you download the movie files. Webm videos are still somewhat rare on Youtube but here is one of them, if you cannot see it, make sure that you have html5 enabled on Youtube and are using Opera 10.60 or later. (Opera Mobile and Mini don' t support html5 video yet)
If you are already using a custom stylesheet for youtube and do not want to replace it with this one, simply copy its contents to the file you're already using.
Bear in mind, though, that many media players do not yet support .webm files, if you have trouble playing the files on your PC, download an install VLC media player, they definitely work in that and it is available on all platforms.