The emerging Peer-to-Peer (P2P) model has becomea very powerful and attractive paradigm for developing Internetscale systems for sharing resources, including files and documents. The distributed nature of these systems, where nodesare typically located across different networks and domains,inherently hinders the efficient retrieval of information. In thispaper we consider the effects of topologically-aware overlayconstruction techniques on efficient peer-to-peer keyword searchalgorithms. We present the pFusion (Peer Fusion) architecturethat aims to efficiently integrate heterogeneous information thatis geographically scattered on peers of different networks. Ourapproach builds on work in unstructured peer-to-peer systems,and uses only local knowledge. Our empirical results, using thepFusion middleware architecture and datasets from AKAMAI,NLANR and TREC, show that the architecture we propose isboth efficient and practical