Austin, I agree with communities of interest as that is what most of my social interactions on the internet (other than e-mail) have been since 1992. But, the venue does make a difference and have been an many groups on various services that either up and moved to another or started a new group (some reasons were the platform (restrictions, functionality, or price driven move) other related to human social dynamics. The technology/service adds a layer to the conversation.On the front of people moving in physical life and losing connection I know many people who do not see the same thing having to happen in the digital realm. They may move services but still expect their friends to be there or have access to them from their new service. Many have been using SMS, IM, e-mail, etc. and the service does not matter the people do. It is important for many people to keep their friends and contacts (hopefully holding on to contextual interest, this was a trigger for my granular social network post years ago) and they expect that to happen. I agree there is value in the connections of connections, but the first thing most people do on a new social service is track down their friends and contacts to connect to the conversation and interact.Jay, I think the portable people aggregators are a different beast. While the novelty of looking around for friends is a past time for some it is the cost that keeps people from switching services. This is not really many people’s interest until their friends have moved on to another service.