By using a couple of bookmarklets, you can easily download any YouTube video to your computer without the use of any other software. Once you have the video downloaded, you simply rename the file and it’s set to go.
Note: the credit for the great javascript behind the bookmarklets goes to Lawrence Albert at Unlock for This
1. Open Chrome.
2. Right-click the Bookmarks bar and select Add Page.
3. In the Name textbox, input the word Download FLV.
4. In the URL textbox, input the following:
javascript:window.location.href = 'http://youtube.com/get_video?video_id=' + swfArgs['video_id'] + "&l=" + swfArgs['l'] + "&sk=" + swfArgs['sk'] + '&fmt_map' + swfArgs['fmt_map'] + '&t=' + swfArgs['t'];
5. Make sure that the Bookmarks bar folder is selected and click OK.
6. Right-click the Bookmarks bar and select Add Page.
7. In the Name textbox, input the word Download MP4.
8. In the URL textbox, input the following:
javascript:window.location.href='http://youtube.com/get_video?video_id='+swfArgs['video_id']+"&fmt=18"+"&l="+swfArgs['l']+"&sk="+swfArgs['sk']+'&fmt_map'+swfArgs['fmt_map']+'&t='+swfArgs['t'];
9. Make sure that the Bookmarks bar folder is selected and click OK.
Rename the downloaded file to a appropriate name. You will also need to add the .flv extension to the downloaded FLV file.
OR just drag these links to your Bookmarks bar:
To fix the icons for your newly created bookmarklets, follow the instructions here.