In the www architecture corner, this email from Roy Fielding to Tim Berners-Lee on URIs and resources is view-changing. Fielding's position is that a URI is an opaque reference to a resource and a web page is just one representation of that resource. It's a shift away from Berners-Lee's position that a URI is an identifier for a document, and that document comprises the resource itself. This small change in metaphor gives quite a good lever for understanding and building things on the www, and leads almost directly to the REST architecture.