Facebook launches "Friendship Pages," which "contain the public Wall posts and comments between two friends, photos in which both are tagged, Events they RSVP'd for together and more." "You'll be able to see a friendship page if you're friends with one of the people and have permission to view both people's profiles.
When it's between two people who share a lot, the page really starts to reflect their friendship. You can find a friendship page from links under relevant Wall posts, under relationship stories and under the main photo on a friend's profile page," explained Facebook.
Facebook, on the other hand, is framing these pages as "telling the story of friendship," and furthering the company's mission of connecting friends. Wayne Kao, says they're designed to bring out the human side of Facebook and bring back memories you've shared with friends.