You simply add the URL from the YouTube video or one of several other video services supported at Video2mp3, click convert and it spits it an URL where you can download the mp3 file. This may be working well for lengthy speeches for example that you can then listen to

Convert your favorite YouTube videos to high quality mp3s and also download the videos directly. Dirpy provides many useful features like real-time transcoding, id3 metadata tags, offsets, support for high quality formats (including HD), and more. Dirpy is also search tool to help you find files like music, videos, archives,