I’ve just started playing around with Soundrop, which is collaborative playlist/DJing. Basically, you can join a “room,” and add tracks to a room’s playlist, vote on tracks that you want to hear, and chat with other people who are in the room and listening. It has some potential to be a fun way to share music with like-minded folks. I’m using it with Spotify, although I think it might also have a plain old web interface for those who aren’t Spotify members.
Anyway, I created a Stumbling in the Dark room here: http://open.soundrop.fm/s/XU28YSR2l4Bgztxk. Come on over and share a few tracks!