Most of the time we spend on Internet is on Social Networking sites and browsing videos on youtube, metacafe etc. To download videos from these sites, there are some sites savevid, keepvid etc. but to download videos from here is a bit tricky.You have to copy your video url and then paste it in these sites to download. There are some softwares also,ofcourse IDM being the best among them. But there is yet another way to download videos from any site if you are using Firefox. This is a add-on from firefox and you can use it for as long as you want. Here is what you will have to do-
1. Just open your firefox browser.
2. Click here to download the add-on.
3. Firefox will ask you to restart firefox. Click on Restart Firefox.
4. After restarting you will see an icon on upper side of your browser.
5. Open any video site and play the video you want.
6. To download that video,just click on FVD icon and video will start downloading.