From Inside Facebook:
Facebook has added a “Listen Later” button to Open Graph music stories in the feed, allowing users to fill out a new section of their About page.
The feature becomes available when users hover over a story about friend’s listening activity on Facebook-connected services like Spotify or Rdio. Users can click the small plus sign, which will bring up the “Listen Later” option and a way to adjust the privacy settings of the story. We have not seen examples of “Read Later” or “Watch Later” buttons in the feed, but these could be coming or already in testing, considering that the new About page also includes “Want to Watch” and “Want to Read” sections.
Continue reading the rest of the story on Inside Facebook