In the past, when the commercial world was relatively stable and the future plannable, organizational structure was appropriately the principal instrument of strategy. Now that strategy is more about intent than long-term plans, more about pasting and prototyping than planning for D-Day, companies need to start preparing for the future differently. The paper arises from a 98-corporation study of building e-business infrastructure. A particularly complex and pervasive issue was the fit between technology infrastructure and strategic intent and structure. Several companies were observed to be developing what we call here an Organizational Architecture capability to manage the problems they experienced. Here, using the case study base, we develop the rationale and content of such a capability, and show its key tie in to leveraging IT applications and infrastructure.