As always in real estate, everything in technology these days seems to be about location. From Google's recent addition of a "nearby" location limit to its suite of search options to the spate of location-based mobile apps and social networks, physical proximity has become the linchpin of a trend to connect technology to the real world. In this article, the author discusses location-based social networks that can be used for libraries. As librarians and libraries explore uses for Foursquare and other location-based tools, the author stresses that it's necessary to consider the privacy and security implications for patrons. Though playing a game through Foursquare could be a great way to introduce patrons to the library, exploring the physical library through QR codes linked to tips and resources might be a more comfortable technology-real space connection for many. (Contains 6 online resources.)