Hi,

There are actually different FVD you can use. Why don't you try to use extension, just consider the browser you are using. You can also use this:

ClipNabber allows you to download videos from YouTube, Metacafe, etc by simply copying and pasting the URL. You’ll then get a link whereby you can download the file to your computer, iPod, iPhone, or any other media player. You’ll need to have an FLV player for the YouTube videos. Quick and very easy to use!