Online social communities are increasingly used as platforms for manifold forms of interaction and information sharing, both in real-time and asynchronous. The prospect of coupling social computing with sensing capabilities of current mobile devices makes it possible to provide social applications with higher degrees of context-awareness, detection of activities of individuals and groups, as well as implicit social interaction through sharing of context-sensitive information. In addition to the pervasive context obtained from the mobile devices, the links and user interactions in social networks can be regarded as rich sources of information for pervasive applications. Mobile Social Gateway (MoSoGw) is a web service that provides a generic interface for optimized information transfer between mobile devices and different social networks, as well as third-party web services. Its interface is generic in that it makes transparent to the mobile client application the interaction with social networks and web services. Performance and scalability were major concerns when designing and implementing MoSoGw. Hence, its architecture and all technologies used in its development have been carefully chosen so as to scale to thousands of clients and support high volume of concurrent requests.