Downloading Clips From YouTube Without Any Tool

As you know, YouTube is a movie sharing service on the web. Lots of people upload their clips on it. I think its a two-sided knif: It can be harmful or useful. (like other web services!)

Here I'm going to tell how to download movies from YouTube to you hard disk and keep it forever for yourselves.

Assume this URL:
http://www.youtube.com/watch?v=QYy6fIk3A20

Open this URL by your favorite web browser. Wait until the page (not movie) loaded. Then go to "Page Source". Search for "video_id". You'll find something like this: (Don't pay attention to other search results, you need only the fullscreenUrl):

var fullscreenUrl = '/watch_fullscreen?fs=1&vq=None&video_id=QYy6fIk3A20&l=35&sk=nx42RolSOgvEwZkzlA1RKeus1v19_fNMC&fmt_map=&t=OEgsToPDskLlRMjJ2joW3LqApGKpwLcY&hl=en&plid=AARNovEMmwHAvd6yAAAAgAAAAAA&title=a beginning for my FPGA studies, part 2';

Just copy the front term of video_id:

QYy6fIk3A20&l=35&sk=nx42RolSOgvEwZkzlA1RKeus1v19_fNMC&fmt_map=&t=OEgsToPDskLlRMjJ2joW3LqApGKpwLcY&hl=en&plid=AARNovEMmwHAvd6yAAAAgAAAAAA&title=a beginning for my FPGA studies, part 2

At last make your final downloadable URL as below:

"http://www.youtube.com/get_video?video_id=QYy6fIk3A20&l=35&sk=nx42RolSOgvEwZkzlA1RKeus1v19_fNMC&fmt_map=&t=OEgsToPDskLlRMjJ2joW3LqApGKpwLcY&hl=en&plid=AARNovEMmwHAvd6yAAAAgAAAAAA&title=a beginning for my FPGA studies, part 2"

The name of your file would be the name becomes in front of title (in the video_id):
a beginning for my FPGA studies, part 2.flv

You can also download your movie with "DownloadHelper" extension of Firefox. This extension works exactly with the above method!

Thanks to ggarron for its article.