creepy when adults have facebooks," her daughter instant-messaged her. "unfriend paige right now. im serious.... i will be soo mad if you dont unfriend paige right now. actually." In fact, social networking sites are not only for the young. More than half of the visitors to MySpace claim to be over the age of 35. And now that the first generation of college Facebook users have graduated, and the site is open to all, more than half of Facebook users are no longer students. What's more, the proliferation of niche social networking sites, including those aimed at adults, suggests that it is not only teenagers who will nurture relationships in virtual space for the foreseeable future. What characterizes these online communities in which an increasing number of us are spending our time? Social networking sites have a peculiar psychogeography. As researchers at the Pew project have noted, the proto-social networking sites of a decade ago used metaphors of place to organize their members: people were linked through virtual cities, communities, and homepages. In 1997, GeoCities boasted thirty virtual "neighborhoods" in which "homesteaders" or "GeoCitizens" could gather -- "Heartland" for family and parenting tips, "SouthBeach" for socializing, "Vienna" for classical music aficionados, "Broadway" for theater buffs, and so on. By contrast, today's social networking sites organize themselves around metaphors of the person , with individual profiles that list hobbies and interests. As a result, one's entre into this world generally isn't through a virtual neighborhood or community but through the revelation