Friendster and Publicly Articulated Social Networks by danah boyd - a 2004 short CHI paper staking out what Friendster is.Link
Abstract: This paper presents ethnographic fieldwork on Friendster, an online dating site utilizing social networks to encourage friend-of-friend connections. I discuss how Friendster applies social theory, how users react to the site, and the tensions that emerge between creator and users when the latter fails to conform to the expectations of the former. By offering this ethnographic piece as an example, I suggest how the HCI community should consider the co-evolution of the social community and the underlying technology.
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.