After some comments from Bigpresh I have joined Facebook. It's got some neat features, such as tagging people in pictures and lots of optional add-ons. I've linked to a few people now and there are many others I know on there. The numbers just seem vast. Even a search for a rare surname often returns loads of people, so finding people can be tricky unless they are friends of a friend. A limitation is that you cannot see much there until you join up. This may be to reduce spam.

I will still keep my Multiply page as I can't face trying to persuade friends and family to learn another system when they haven't got to grips with that one. There will some duplication of contacts, but Facebook seems to encourage more activity, especially among the geekier element.