Video site Youtube is now featuring Live Events, video streams broadcasted using a user's profile. These events range from music to sport, politics to animation. Boiler Room, a channel featuring recorded sets by obscure DJs and huge names in music alike, often features live streams, from small bedroom DJs with recognisable skill through to big-name music producers. From their page you can see upcoming streams, what's being streamed live, and what has been saved to video. The live stream allows you to watch what's being filmed from anywhere in the world. It also lets you participate in a comment feed, to engage with the uploader during their event.
It's still early days for Youtube and the Live Events streams I investigated frequently seemed to experience technical difficulties, but I can see this feature substantially changing the face of social media.