  In this paper we study the impact of data that can be obtained from a Charm
Factory on the determination of the CKM parameter gamma from decays of the form
B -> D0 K where the D0 decays to specific inclusive and exclusive final states.
In particular, for each exclusive final state $f$, the charm factory can
determine the strong phase difference between D0-> f and D0-bar -> f by
exploiting correlations in psi(3770)-> D0 D0-bar. This provides crucial input
to the determination of gamma via the interference of B+- -> K+- D0 -> f with
B+- -> K+- D0-bar -> f. We discuss how the method may be generalized to
inclusive final states and illustrate with a toy model how such methods may
offer one of the best means to determine gamma with 10^8-10^9 B-mesons.
