DOWNLOAD YOUTUBE VIDEOS BY EDITING THE YOUTUBE LINK

Normally I will suggest you to get "Video download helper" addon of firefox for downloading youtube videos if you use your own pc. But if you are in hurry or in another pc with limited access, then its a great way to  download  youtube videos.

If your youtube download link is : 

http://www.youtube.com/watch?v=9kCinKpY2MM

Then you will type:

•  http://www.voobys.com/watch?v=9kCinKpY2MM

•  http://www.okyoutube.com/watch?v=9kCinKpY2MM

•  http://www.kissyoutube.com/watch?v=9kCinKpY2MM

Change is highlighted in Blue color.

Beside this, I am giving some website link from which you can download youtube videos easily. All you have to do is - paste your youtube video's link at their site.

http://keepvid.com/
http://www.videodl.org/
http://www.downloadyoutubevideos.com/
http://www.techcrunch.com/get-youtube-movie/