Few days ago YouTube started serving videos in two resolutions Normal and High, the higher resolution version is encoded in MP4 format and therefore can be used directly onto devices supporting MP4 video format like newer iPod's, iPhone's and mobile devices without any video format conversion.
Downloading videos is very easy, just install this Greasemonkey script and you should see a link as shown below for the download, you will need to manually add the .MP4 file-extension.
May 29, 2009
Thanks for update
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