Community is a hackneyed phrase. It is like the word ‘democracy’ or ‘friends’ or ‘freedom’; the more it is spoken, the less of it there is. There is a lot of talk (again) about online communities; especially considering that it is a central component of Web2.0. But what is a community? I grew up in a community; in a small island on the edge of the Western world. It was fun for a while, but then I discovered that it had boundaries. The word community is often applied to individuals who exchange opinions and text online, but is this a community or is it just sending text? Can we understand online communication without the need for the word community? I hope so. I like the German word Gemeinschaft much more. It refers to a ‘community of belief’. It has religious undertones, just like the bad old days of Web 1.0. An online community is just a belief; and belief all too often overrides truth. The belief is that the online community actually exists; in a word where’ social capital’ and community is on the decline.
By all means start a Wiki, but please don’t call it a community. A community requires boundaries and as soon as you believe that online messages and communication is a ‘community’; you are missing the real one in which these activities are embedded.Here

Here is an article ZDnet on how to get people to use your Web 2.0 applications. Also here is an a new system called Wikipatterns that is built on the assumption that communication is not good nor bad nor is it neutral. (Or, you have a right to be a Libertarian, but I have a right not to be killed!).