youtube-dl

Version: 2008.09.20 youtube-dl is a small command-line program to download videos from YouTube.com.

You can change the file name of the video using the -o option, like in youtube-dl -o vid.flv "http://www.youtube.com/watch?v=foobar".
Some videos require an account to be downloaded, mostly because they're flagged as mature content. You can pass the program a username and password for a YouTube.com account with the -u and -p options, like youtube-dl -u myusername -p mypassword "http://www.youtube.com/watch?v=foobar".
The account data can also be read from the user .netrc file by indicating the -n or --netrc option. The machine name is youtube in that case.
The simulate mode (activated with -s or --simulate) can be used to just get the real video URL and use it with a download manager if you prefer that option.
The quiet mode (activated with -q or --quiet) can be used to supress all output messages. This allows, in systems featuring /dev/stdout and other similar special files, outputting the video data to standard output in order to pipe it to another program without interferences.
The program can be told to simply print the final video URL to standard output using the -g or --get-url option.
Combined with the above option, the -2 or --title-too option tells the program to print the video title too.
The default filename is video_id.flv. But you can also use the video title in the filename with the -t or --title option, or preserve the literal title in the filename with the -l or --literal option.
You can make the program append &fmt=something to the URL by using the -f or --format option. This makes it possible to download high quality versions of the videos when available.
youtube-dl can attempt to download the best quality version of a video by using the -b or --best-quality option.
youtube-dl honors the http_proxy environment variable if you want to use a proxy. Set it to something like http://proxy.example.com:8080, and do not leave the http:// prefix out.
You can get the program version by calling it as youtube-dl -v or youtube-dl --version.
For usage instructions, use youtube-dl -h or youtube-dl --help.
You can cancel the program at any time pressing Ctrl+C. It may print some error lines saying something about KeyboardInterrupt. That's ok.