Web 2.0 functionality is changing the way consumers search for, evaluate, and use health information. What are some of the new “Consumer Health 2.0” sites and their features? How will this trend toward participatory information processing affect traditional sites such as the National Library of Medicine's MedlinePlus? How should librarians approach this new paradigm of health information-seeking? This article analyzes the current and potential environment for health information on the Internet and the role of the librarian in that environment.