  We propose to entangle macroscopic atomic ensembles in cavity using
EPR-correlated beams. We show how the field entanglement can be almost
perfectly mapped onto the long-lived atomic spins associated with the ground
states of the ensembles, and how it can be retrieved in the fields exiting the
cavities after a variable storage time. Such a continuous variable quantum
memory is of interest for manipulating entanglement in quantum networks.
