The Mellon Foundation-funded Linked Data for Libraries Labs (LD4L-Labs) and Linked Data for Libraries Production (LD4P) projects are exploring the library community’s transition to Linked Open Data. Authority and identity lookups are integral to cataloging workflows and provide excellent opportunities for exploring how to leverage the power of Linked Data for reconciliation and more effective lookups. Central questions in this work include the implementation, performance and reliability of lookup services; what multiple authority lookups mean with respect to reconciliation; and user interface design. We are currently experimenting with caching mechanisms that address the issues of access, reliability, and speed, including an approach that uses a Linked Data Fragments server for caching and serving up authority results. We are also exploring the implementation of a containerized and potentially mirrored search index populated using Jena and Fuseki to execute SPARQL queries against Linked Data sources. We are extending the Questioning Authority (QA) work being developed for the Hydra repository to enable more configurable Linked Data lookups that can be used across different technology stacks. VitroLib, an experimental cataloging tool being developed using the Vitro platform, integrates QA lookups to support catalogers searching for and linking to authorities. We will demonstrate the lookup configuration and integration into both the Hydra repository and VitroLib. All the software is open source.