UnPlug is an Firefox extension, lets you save video and audio which is embedded on a Web page - its a video download tool. UnPlug scans Web pages and tells you where media players are getting their data from, and displays it as a simple hyperlink: in most cases, you can then follow the simple download link to save the media file.
UnPlug works for lots of sites including youtube.com, ifilm.com, current.tv, revver.com, peekvid.com, video.google.com, mobuzztv.com, and more. Unlike many other extensions, UnPlug scans the page, and if it doesnt know there the data comes from it can guess - correctly most of the time.

The license of this software is Freeware, you can free download and free use this browser plug-ins software.