Geographic communities: range from the local neighbourhood, suburb, village, town or city, region, nation or even the planet as a whole. These refer to communities of location.
Communities of culture: range from the local clique, sub-culture, ethnic
group, religious, multicultural or pluralistic civilisation, or the global community cultures of today. They may be included as communities of need or identity, such as disabled persons, or frail aged people.
Community organizations: range from informal family or kinship networks, to more formal incorporated associations, political decision making structures, economic enterprises, or professional associations at a small, national or international scale.
When Gil said that he didn't think the Jewish blogosphere is a true community the angels cried (Disagree) (I think he's dead right. Lots of different communities may exist within the J-blogopshere, but the J-blogosphere is not a community itself: We don't have common interests, and no one views the blogosphere as a distinct segment of society. We speak of aliya-nics, or skeptics, or TorahTrue-niks, not of "Jewish bloggers")
Is Judaism today a community itself? Is Israel a community itself? When R' Gil said he wouldn't want to expose his readership to the "Haveil Havalim" blog carnival, does that mean he is anti-community? Of course not.
The lowest common denominators of Judaism and Israel today have eroded down to close to zero. What do Neturai Karta and Humanist Judaism have in common? The Chadash political party and Tekuma? The Treppenwitz blog and Lisa Goldman? DovBear and the Muqata? Jewlicious and Netanyahu (well, we know one is much funnier than the other one)
Wherever I am, my blog turns towards Eretz Yisrael טובה הארץ מאד מאד