Metafilter Music is online. It's a place for members of the Metafilter community to post their songs and of course anyone can listen in. There's all the usual Metafilter goodness we've come to expect: tagging, commenting, favorites and RSS feeds as well as additional features like playlists and podcast feeds. I really like the playlisting feature, it makes it easy to navigate the music on the site and fun to explore in a Flickr-like way. If the community remains enthusiastic about it, I think it'll be something special.