The objective of this work is to build a data-sharing application for an ad-hoc network of mobile devices, where users can exchange data/files among themselves without relying on traditional communication channels like telecom or network operators. In other words, we aim to build a mobile cloud service for data sharing. This paper examines the resource discovery and selection (also called replica selection) issue in such a mobile cloud. We propose a novel decentralized algorithm where nodes can first discover and then choose the best replica to request for, from among the different alternatives identified. Additionally, our paper comes up with a new metric to evaluate different replicas, that is, what could be a desirable definition of the 'best' replica in such a network.