yeah, it's possible, and definitely easy to do. first, get firefox. if you have it already, then click on this link and download the addon:
Code:
https://addons.mozilla.org/en-US/firefox/addon/3006
Once you have downloaded it, install it, and then restart firefox. Then go back to the site you wanted the video from, and click play. Up by your userbar, you'll see 3 spinning dots, click on it, and click the link it provides. Now you are downloading that video