Since its widespread public adoption in the 1990s, the internet has inextricably woven itself into every facet of human existence, influencing and in some ways reshaping every aspect of modern life--people's communication patterns, the way people seek information, the way people think, and, in some instances, the way people act. It is highly unlikely that one would find a person working in a library, or in any other organization for that matter, whose professional and personal life had not been affected by the internet. Based on statistical evidence, it is easy to understand why the web has been characterized as the "new normal" in the average person's way of life; those who don't go online constitute an ever-shrinking minority. It is within such an environment that people have seen the emergence of a new era of web-enabled applications that are built around user-generated or user-manipulated content and commonly referred to as Web 2.0. Web 2.0 refers to a perceived second-generation of web-based services--such as social networking sites, wikis, communication tools, and folksonomies--that emphasize online collaboration and sharing among users. Library experts have used simpler terms to describe the Web 2.0 phenomenon: (1) the read/write web, where users are both consumers and producers of online content; (2) an interactive two-way web; and (3) a place where everyday folks with internet access can create and edit material. In this article, the author discusses the Web 2.0 revolution, the analogous derivatives it has spawned such as Library 2.0, Library User 2.0, and Librarian 2.0, and how Web 2.0 technologies may be integrated into library services.