Add-ons are a great feature of Firefox. It allows you to install small applications (widgets) to work with Firefox to do more tasks that Firefox can’t do alone (yeah, there are quite a handful). Like Firefox, they’re free! The VideoDownloader add-on is one of them. You can get it here.

And here’s a cool instructional video on how to use it.

Using VideoDownloader, you’d easily be able to save embedded videos. You can now play them as video files on your PC using your preferred media player.

If you happen to download Youtube videos, you might be saving FLV files (or VideoDownloader may prompt you to change the file extension as such).

To play back FLV files offline, you need an FLV player like nFLV Player. It’s freeware!