  Some years ago, a method was proposed for measuring the CP-violating phase
gamma using pairs of two-body decays that are related by U-spin reflection (d
<-> s). In this paper we adapt this method to charmless B -> PPP decays.
Time-dependent Dalitz-plot analyses of these three-body decays are required for
the measurement of the mixing-induced CP asymmetries. However, isobar analyses
of the decay amplitudes are not necessary. A potential advantage of using
three-body decays is that the effects of U-spin breaking may be reduced by
averaging over the Dalitz plot. This can be tested independently using the
measurements of direct CP asymmetries and branching ratios in three-body
charged B decays.
