We characterize the dynamic data management problem for location based services (LBS) in mobile environments and devise a cost model for servicing both location independent and location dependent data. The cost analysis leads to a set of dynamic data management strategies that employs judicious caching, proactive server pushing and neighborhood replication to reduce service cost and improve response time under changing user mobility and access patterns. Simulation results suggest that different strategies are effective for different types of data in response to different patterns of movement and information access.