honestly i didnt searched but..from what i see ppl still use websites and other programs to download video from youtube. here i have another method which simply ,through a script and a plugin of firefox,let u download them directly as mp4.
Step 1: You must begin by installing GreaseMonkey and you must be using FireFox.(https://addons.mozilla.org/en-US/firefox/addon/748)
Once it is installed. Click "Restart Firefox".
Step 2: Click on this link to download the YouTubeLoader script.(http://userscripts.org/scripts/source/21774.user.js)
restart FF. if u done everything properly when u look at a video in youtube u should find an option below the info of the file saying download as mp4.
credit goes to this site dunno who's the author http://www.youtubeloader.com/firefox_plugin.php#youtubeloader here u find complete guide for retards with screens included