Check out http://www.downloadhelper.net. I have that installed and it's great - lets me download youtube videos and any other embedded video online, including the vids on the trick pages.
It's just a little icon in your firefox toolbar - when a video starts streaming, the icon will light up and spin around. Click the little arrow next to it and there will be a list of the videos currently being downloaded - click the vid you want (like 360-front-kick.flv for example) and it'll save to your desktop.
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