Online directories and other online instruments can serve multiple purposes in libraries. Not only can they assist reference librarians in locating data for patrons, but they can also serve as resources in building in-house databases. The process of building the goLocalUtah (gLU) database utilized a variety of online directories and other resources. This article outlines this process and includes valuable information learned about these resources and their varying degrees of usefulness, and a discussion of potential applications in health sciences and public libraries. The authors also list online directories and other similar tools that they found to be especially valuable.