  We consider the implementation of an arbitrary unitary operation U upon a
distant quantum system. This teleportation of U can be viewed as a quantum
remote control. We investigate protocols which achieve this using local
operations, classical communication and shared entanglement (LOCCSE). Lower
bounds on the necessary entanglement and classical communication are determined
using causality and the linearity of quantum mechanics. We examine in
particular detail the resources required if the remote control is to be
implemented as a classical black box. Under these circumstances, we prove that
the required resources are, necessarily, those needed for implementation by
bidirectional state teleportation.
