To be successful and truly collaborative, knowledge-sharing systems require intuitive tools that connect people, reward participation, and align well with existing work and communication patterns. After IDEO's two-year internal development effort to create and implement "the Tube," their enterprise-wide intranet system, we gained new understanding and experience in balancing technology possibilities with behavior realities. The unique success of the Tube comes from the insight that effective knowledge sharing is a social activity that is enabled by technology, rather than a technological solution bolted onto an existing work culture. Now IDEO's Knowledge Sharing Team shares a set of design principles for building online collaboration systems that really work