  We propose to use a large cloud of cold trapped ions as a medium for quantum
optics and quantum information experiments. Contrary to most recent
realizations of qubit manipulation based on a small number of trapped and
cooled ions, we study the case of traps containing a macroscopic number of
ions. We consider in particular the implementation of a quantum memory for
quantum information stored in continuous variables and study the impact of the
relevant physical parameters on the expected performances of the system.
