Cogent Explanation Of Web 2.0

Someone called their blog "Read/Write Web", and that is a succinct description of what is being referred to as "Web 2.0".

Originally the Web was "read-only" -- the average person did not have the tools to put things on the web -- they would simply read webpages that companies and web enthusiasts would put on the web.

But now the Web is read/write -- there are all sorts of tools that make it trivial to write information to the web (often without cost): wikis, blogs, comments, podcasts (well, that needs to be made simpler), Flickr, del.icio.us.