Purpose: This paper aims to present a practitioner overview of the challenges and growing strategic importance of knowledge and knowledge sharing in organizations, considering roles of learning, and in particular networks, together with collaboration in the development of sustainable competitive edge through knowledge, knowledge management and the activities of knowledge workers. Design/methodology/approach: First, the paper sets the scene for the development of the twenty-first century knowledge economies, by providing a brief literature overview incorporating some of the key work of Peter Drucker, Charles Handy, Tom Stewart and others. It also provides insights into the London Knowledge Network and its role in supporting organizations in the pursuit of effective knowledge-focused strategies. Then, via insights into three organizations: one medium-sized private company (US) and two public (one small, one very large) UK organizations, some of the challenges are considered that organizations experience as they seek to use learning and knowledge as sources of sustainable competitive edge at organizational and often regional, national, international and global levels. Findings: Overall, it was found that knowledge management has not become the latest management fad but, if properly supported, can be used to benefit customers and workforces alike. Originality/value: Some conclusions are drawn about how organizations are managing the significant change, especially the cultural change, involved in using knowledge as a key driver for future competitiveness. This paper will be of use to any organization wishing to implement knowledge management.