$ sudo apt-get install youtube-dlCommand to download
$ youtube-dl [options] video_urlIf you're getting an error as "ERROR: unable to download video (format may not be available)", get latest version of youtube-dl from github.
Set execute permission
$ chmod +x youtube-dl-latestExecute the latest version script to download video
$ ./youtube-dl-latest [options] video_urlNote:
Tested on Linux Mint 10 64-bit.
Found out an easy way. Install video download helper addon for Mozilla Firefox. Works perfectly on both Linux and Windows.