I used Firebug, an debugger extension tool for Firefox. See my post #6 for info and that YouTube I linked to on how to find/select it.
If you look at the Page Source instead, to try to find the EMBED/OBJECT, it won't work. That is because they use Javascript to decode a set of data (that is not HTML) and use that to dynamically build up their OBJECT/EMBED, then attach that programmatically to the YouTube page.
And if you try in Safari, they detect that and instead use HTML5's VIDEO tag.
BTW, I see they took down Gasland due to an infringement complaint.
If you just need one video, post a link and I'll try to get the code for you and post it back here.