Downloading YouTube Videos with a Perl One-Liner

Addendum:

There is a Microsoft Research (command line) tool (actually it's several) that is quite good for nicely formatted HTTP conversations: it's called STRACE. It comes with an HTTP replay utility as well. You can also use a special wininet.dll with MSIE that MS Research released many years ago.

The tool we really need though is one that has all the 'handshaking' (redirections, javascript, swf, etc) capabilities of Mozilla coupled with built-in 'livehttpeaders' functions, and _nothing else_. No rendering engines and other bloat. This tools would get you the URL to the content. That is its sole job. Then you download the content with a tool that works (unlike the download mamagers of the browsers). And finally you play the content offline with a standalone tool that works on any media file (you should know which ones can do that from your own experience trying different ones).

Alas, the developers seems to think they can include all these steps in one application ("plugins") and have it work, seamlessly... instead of following the UNIX way of letting each tool do its job and piping the task from one application to the next.

Advertising (after all we do need that right?) can be 'attached' to the content.
An example is the TED videos, where you see a BMW ad at the start of each video.

This has been said before by people smarter than me: all the html tags flowing through the 'wire' are largely unnecessary, and slow things down. Almost all value is in plain text and links to more text or to content. 'Typesetting' (e.g. html gimmicks) is only residual value.