youtube extension

Is there an extension or something for MOC so that it can stream/play the audio parts of youtube videos.

Not specificly, and nor am I planning on adding it. But setting the
YouTube video MIME type to point at the FFmpeg decoder and playing
the URL might work.

See the 'PreferredDecoders' configuration option and you'll need MOC
built from the current SVN.

Also see: http://moc.daper.net/node/823

Let us know if that works for you.