Spotify has introduced a host of new social networking features and moved to protect itself against rumored future iTunes features.

Spotify’s new library feature lets users store music collections on Spotify, simply by importing any MP3 on your drive to the Spotify library. While this doesn’t mean your tracks are uploaded to the service, it does mean you end up being able to access it using any Spotify-compatible device – leave your tracks at home.

Built on the back of Facebook Connect, Spotify users will now be able to connect to their Facebook page and import friends from their profile who are also registered Spotify users.

Additional features:

• Playlists can be shared and published when created.
• Playlists can be subscribed to in one click
• Friends who have subscribed are visible in a submenu.
• Tracks or albums can be grouped into a favorites folder.
• Users have an inbox to which tracks can be dragged and dropped for recommendation.