Social networks for sharing media

Mediachest.com: Organize, borrow, loan, and share books, CDs, DVDs, and video games
Perhaps chapter 8 should tackle other forms of socializing beyond dating, essentially anything that is personal or friendship-oriented, as opposed to professional and business-oriented?
If I haven’t linked to Flickr yet, I should have. It’s kind of like Orkut but with some actual functionality beyond ghost-town bulletin boards, primarily image-sharing and live chat.