This chapter investigates whether information technology tools typical of Web 2.0 can support Knowledge Management (KM) practices in organizations. An investigation on the Web is conducted and the appropriate literature examined. The information technology tools employed in organizations nowadays are discussed with the help of three guidelines which each present two opposing ideas: knowledge creation versus knowledge sharing, tacit knowledge versus explicit knowledge and hierarchical KM versus organic KM. It is argued that these tools reveal an innate contradiction: they are based on a centralized conception and production but aim to deal with informal, fluid processes, which resist structuring. The term Enterprise 2.0 is defined and examined, since it brings out a critical view of traditional KM technology. In this context, the prevailing technologies on the Web are described as well as the associated use practices. The technologies and practices highlighted are those that enhance the collective creation of information and knowledge-intensive products and the active, rich user participation which influences the development of own technologies. Subsequently, many Web 2.0 tools and services that are, or could be, used in KM practices are described and the sites that provide them are indicated. It is noted that these new technologies are inducing cooperative and decentralized work processes that lead to emerging products of high quality and complexity. Furthermore, they are characterized by net effects, simplicity, ease of use, low cost and rastreability. Nevertheless, there are some difficulties in the application of Web 2.0 technologies, among them, the attainment of performance requisites, privacy and security, the possible emergence of counterproductive results and the need to motivate people to create content. The challenges and opportunities in the organizational use of Web 2.0 technologies are remarked. Finally, the managerial interventions appropriate to enable the success of KM projects based on Web 2.0 technologies are discussed. Chapter 8.11 Could Web 2.0 Technologies Support Knowledge Management in Organizations?