  The rare decay B -> X_s gamma gamma is studied in the Standard Model (SM) and
in two different versions (Model I and Model II) of the Two Higgs Doublet Model
(2HDM). In the SM the branching ratio into ``hard photons'' is about 10^(-7)
and can be appreciably different in the 2HDM. We also introduce a
forward-backward asymmetry which gives an additional handle to discriminate
different models.
