If you want to download YouTube videos or convert YouTube video to MP3 format on Elementary OS Luna, Clipgrab is for you. Clipgrab is a multi platform YouTube downloader and converter with simple GUI. I have been testing Clipgrab 3.4.2 on my Elementary OS Luna and it works perfectly except the unsupported ffmpeg version I have which cause downloading video in 1080 resolution is not possible.
To download YouTube videos, you must first install Clipgrab on Elementary OS Luna. My previous tutorial on How to install Clipgrab 3.2 on Ubuntu 14.04 should work as well on Elementary OS Luna. Once installed, open ClipGrab and enter/type keyword video you are looking for. ClipGrab will then display the result including video thumbnail on its main window.
Alternatively, you can copy YouTube video url and paste it on the Downloads tab. Select the destination format and quality from the dropdown menu on ClipGrab. To start downloading, press Grab this clip button.
Downloading video on Elementary OS Luna never this easy. Thanks to ClipGrab. Please also note that ClipGrab supports YouTube, Vimeo, DailyMotion, Metacafe websites. And probably many others also supported.