What is Web 2.0?

Lorcan Dempsey has an interesting analysis of Web 2.0 on his Weblog. Noting that the term is a fuzzy one, he points out that it is associated with 'diffusion' (think wikis, blogs, social networking, etc.) on the one hand and, on the other, with 'concentration' (think of the Library of Congress and Australian National Library cooperation with Flickr). This is an interesting analysis, well worth a look.