Web 2.0 refers to all the interactive web sites that have recently become so popular, e.g. blogs, My Space, wikkis, Flickr. Users don’t go to these sites just to get information; they go to these sites with the expectation of interacting with other users on the site. This is done by posting comments, contributing information or interacting in some other way with the people on the site.  Young people are doing this in their sleep.  We “mature” people have to learn.