Download movie from Youtube instanly using Javascript

There are many ways to downlad video files in Youtube. You can use software such as Youtube downloader or Xilisoft Download YouTube Video. The other ways is using plugin or add-ons on your browser, even you can download via url (i.e keepvid.com or youtubecather.com). But the simple and fastest way is using java sript.
Here is the script I apply to download from youtube :

"javascript:b=fullscreenUrl;g=b.indexOf("t=");d=b. indexOf("&hl");h=b.substring(g,d);link="http://www.youtube.com/get_video?video_id=" + pageVideoId + "&" + h;location=(link);void(0)"

Simply copy paste the script above (without quote) to the addres bar in youtube where you want to download the video. For example :

• Let's say you want to donload jimi hendrix hey joe teeth solo
  http://www.youtube.com/watch?v=FWh-lVC5Q_o
• Delete the address bar and copy paste the script to the address bar and press enter
• You will be prompted to save the video to your hardisk

These tips was tested on Firefox 3.0, Opera and Cometbird 3.0 browser