Interestingly, I get the sense that many of these groups are limited in scope to their topic of interest - that they rarely call upon their shared context to work together outside of that defined boundary.
I was referring to online communities like mailing lists and Usenet groups. I see those communities as being more "walled" by their topic-of-interest. This is an unscientific hypothesis on my part. I suspect that when the community is formed more naturally - by my seeking and finding those people - that there is more likelihood of finding shared interests that diverge from the original connections within the community. I think the point of mailing lists and other forums is to stay "on topic" and they have active gardeners who kindly request people take those off-topic conversations elsewhere. This is appropriate - I wouldn't expect my yoga class to devolve into a discussion of film - though it is nice when it happens afterwards (outside the confines of the specific community).
I was thinking out loud that blogs and other personal approaches let one reach into many communities while also retaining a semblance of identity outside all those communities. I can post something here that says something about me and my interests that I might not feel comfortable saying or asking in places that are geared around specific topics.
Does that help, Nancy? And when is Lilia getting back from her holiday to chime in on this one (ping)?
p.s. Nancy doesn't have trackback enabled, but I know she will see this. Just as she knew I would see her question.