One of the most significant challenges introduced by mobile networks is coping with the unpredictable motion and the unreliable behavior of mobile nodes. In this paper, we define the Virtual Mobile Node Abstraction, which consists of robust virtual nodes that are both predictable and reliable. We present the Mobile Point Emulator, a new algorithm that implements the Virtual Mobile Node Abstraction. This algorithm replicates each virtual node at a constantly changing set of real nodes, modifying the set of replicas as the real nodes move in and out of the path of the virtual node. We show that the Mobile Point Emulator correctly implements a virtual mobile node, and that it is robust as long as the virtual node travels through well-populated areas of the network. The Virtual Mobile Node Abstraction significantly simplifies the design of efficient algorithms for highly dynamic mobile ad hoc networks.