We consider a mobile ad hoc network setting where Bluetooth enabled mobile devices communicate directly with other devices as they meet opportunistically. We design and implement a novel mobile social networking middleware named MobiClique. MobiClique forms and exploits ad hoc social networks to disseminate content using a store-carry-forward technique. Our approach distinguishes itself from other mobile social software by removing the need for a central server to conduct exchanges, by leveraging existing social networks to bootstrap the system, and by taking advantage of the social network overlay to disseminate content. We also propose an open API to encourage third-party application development. We discuss the system architecture and three example applications. We show experimentally that MobiClique successfully builds and maintains an ad hoc social network leveraging contact opportunities between friends and people sharing interest(s) for content exchanges. Our experience also pro...