Around 18 months ago I went to a lecture with Jitka by Susan Greenfield where she cast about the familiar idea that the web is making us dumber. It's a hypothesis that people like Nicholas Carr has bandied about as well in his book The Shallows. The idea is that such is the glut of information available online that our attention spans are so stretched that we can no longer concentrate on any one thing and therefore we have become dumber.
As a fully fledged denizen of the web I argued our cause on the way home with Jitka. If this sort of thing interests you then you'll like this video by James Gleick, renowned author and thinker of books such as Chaos and Faster. He suggests that the web will cause us to change how we think, but he doesn't see this as a bad thing. Enjoy (and leave your thoughts in the comments).