Youtube Downloader HD is a file downloader for Windows. It allows you to download video files from the YouTube service. As you might know, YouTube allows you to stream FLV files from their site. If you ever need to download those files to your computer, this application can do just that. Furthermore, recently, the website has been allowing users to upload high-definition versions of their videos to the site and you can toggle between the HD and regular definition versions on the website. YouTube Downloader HD also allows you to download those high-definition videos in a variety of formats. By default, you can download your videos in the regular definition FLV file, and .AVI file (also regular definition), and it adds two formats for HD content. The first one is MP4. This one is compatible with most mobile devices, like iPod, iPhone and some gaming consoles, like Xbox 360, PS3, Wii, etc. The other HD format is AVI, which is supported by most video players as well. Downloading a HD file is as simple as selecting a format, pasting the YouTube URL and hitting Start. It all happens really quick and the HD video's quality is as good as the one on YouTube. I have even experienced faster download speeds with video downloaders than streaming directly off YouTube. Version 1.6 adds several bug fixes, better MP4 and AVI encoding for HD files.