You don't need any special applications, browser add-ons or terminal commands to save YouTube videos in Ubuntu:
1. Open the YouTube video you want in your browser. Let it load completely, with the quality setting you prefer (SD, HQ, HD). Do not close the browser at this point.

2. Open Nautilus and go to /tmp (File System -> tmp). You will find a file named Flash-something. If you have thumbnail previews enabled for video files, it will show up immediately.

3. Copy that file to another folder. Rename it as you please, with the extension .flv (not necessary, it'll just ease up organization and recognition of the file) . You can now close the browser/tab.

4. Click on it, it will play in your media player.

And that's it! What the OMG!U article didn't say, is that it works with other browsers as well (tested it with Chrome), and other pages (DailyMotion). And I'm most certain it works with other distros, too








