Floating Content (FC) is a communication paradigm to locally share ephemeral content without direct support from infrastructure. It is based on constraining the opportunistic replication of content in a way that strikes a balance between minimizing resource usage and maximizing content availability among the intended recipients. However, existing approaches to management of FC schemes are unfit for realistic scenarios with non-uniform user distributions, resulting in heavy overdimensioning of resources allocated to FC. In this work, we propose a new version of FC, called Cellular Floating Content (CFC), which optimizes the use of bandwidth and memory by adapting the content replication and storage strategies to the spatial distribution of users, and to their mobility patterns. The main idea underlying our approach is to partition users into small “local communities”, and to optimally weight their contributions to the FC paradigm according to their specific mobility features, and to the resources required to achieve a target performance level. We characterize numerically the properties of the optimal strategies in a variety of mobility patterns and traffic conditions, showing the accuracy of our approach, and the significant savings it enables in the amount of resources necessary to run FC, which in a realistic setup can be as high as 27% with respect to traditional FC dimensioning strategies.