After all these years of emphasizing the global aspect of the Internet, and how it brings people from diverse locations together online, it seems that local has become more significant. For community networks, the trick is to provide a local structure and vision. But if they can get a picture of it that corresponds to their view of what their community is like, that's a much better hook. This is somewhat controversial. Some have pointed out that people in low-income communities access sites just like everybody else.
Kids are interested in sports and celebrities and things like that, too.
The message to me is that you can't just emphasize the global, you have to go both macro and micro. The article you wrote recently for MIT's Tech Review listed several community networks that are currently active. Training new users is less a problem than training trainers. We've got loads of technically skilled people in Austin. What we don't have are loads of those technically skilled people who know how to train new users.