In (very) short:

Web 1.0 was about: personal web pages, corporate catalogs, content-only journalism, chat rooms, online purchases in online shops, static HTML + dynamic Javascript

Web 2.0 is about: sharing in general (thoughts on blogs, pictures, contacts, etc.) , collective content creation, professionals-amateurs interactions, user reviews, collaborative tools, php + MySQL + AJAX (Javascript + XML), live personalized interfaces (RSS, podcast), VoIP

Web 3.0 will be about: bringing together mobility and Web 2.0; making use of wider broadbands to ensure the integration of Voice, Video, Music, Text, Images, GPS in mobile devices such as cell phones in general, iPods, Blackberries, Blueberries, Strawberries, etc. Tomorrow´s mobile devices will look pretty much alike in terms of functionalities. What about design? Will Apple become the world´s n.1 mobile phones manufacturer?