Youtube download in Chrome

To download videos from YouTube in Chrome browser, make a bookmark with the following address and click on the bookmark while playing the youtube video.

javascript:window.location.href = 'http://youtube.com/get_video?video_id=' + yt.getConfig('SWF_ARGS')['video_id'] + "&l=" + yt.getConfig('SWF_ARGS')['l'] + "&sk=" + yt.getConfig('SWF_ARGS')['sk'] + '&t=' + yt.getConfig('SWF_ARGS')['t'];

This may not work forever, as YouTube keeps changing the methods to get the parameter values.  Stay updated.