Opportunistic networks (ONs) exploit mobility of devices to route messages and distribute information. Unfortunately, the fleeting and intermittent connections between pairs of devices make many traditional computer collaboration paradigms, such as distributed shared memory (DSM), very difficult to realize. DSM systems, developed for traditional networks, rely on relatively stable, consistent connections among participating nodes. We propose a novel delay tolerant lazy release consistency (DTLRC) mechanism for implementing distributed shared memory in opportunistic networks. DTLRC permits mobile devices to remain independently productive while separated, and provides a mechanism for nodes to regain coherence of shared memory if and when they meet again. Simulations using experimentally determined data traces demonstrate that DTLRC is a viable concept for enhancing cooperation among mobile wireless devices in opportunistic networking environments.