It seems social network sites are considered the heart of the internet these days, at least if you’re under 25 (which I’m not); real-life networks still exist of course, especially if you have children (see Tim’s post on Real Social Networks). I’m old-fashioned in that I still use email to keep in touch with people and not exclusively instant messaging (for one thing, lots of the people I email are in timezones 7 or more hours away) and I have enough to do without writing in strangers’ scrapbooks (one big reason I deleted my Orkut account was because I never went there except to delete what people had written in my scrapbook and eventually I couldn’t be bothered any more). For me the big value of a social networking site is being able to keep in touch with people I used to work with (in a company, on some standards committee, or through the XML conference). Given that people in the tech industry move jobs and email addresses with alacrity, I’ve decided to use LinkedIn as a large self-updating address book. This is maybe not the major reason that the site exists, but it’s useful for that. So as I have time I’m searching for names of people I know and sending out invites to “connect” while I still have their email addresses (I’ve already lost touch with lots of people from DOM WG days, for example); fortunately this process can be interrupted when the baby wakes up and demands attention.