You can also create a number of filters to your Timeline: For instance, you can create a history of your music listening and interests over time. Or you could create an “exercise” timeline that reviews your health and fitness activities, and those of your workout partners.

So when does this all become available? The “open graph” (real-time) music, movies, and TV apps will launch today, although Facebook didn’t say which ones. The Timeline tool goes into a beta period today: developers can start using the tool now, but everybody else will have to sign up and wait while the tool rolls out over the next “couple of weeks,” Zuckerberg says.

Zuckerberg and Facebook want to apply the social media approach to many things that we do online -- from news reading to search to business. But dropping an app with the content breadth and flexibility of Spotify into the middle of the social graph could have a profound impact on the way we listen to music and watch video.

Apple's iPod made listening to music a completely closed-off, private experience. Facebook--with big content partners like Spotify and Netflix--could truly make music and video a much more social experience. Imagine a person walking down the street or on a job listening to music with the Facebook app on a smartphone. That person might very well click on a song or a string of songs that a friend was listening to simultaneously while working out at a gym across town. This is a new way to listen to music--it takes the experience out solitary confinement and makes it mobile and social.