Extracting Weak Phases Cleanly from Charmless 3-Body B Decays

In the past, it was believed that one cannot obtain clean weak-phase information from the measurement of CP-violating asymmetries in 3-body B decays. Recently it was shown that this is not true -- by expressing the decay amplitudes in terms of diagrams and using Dalitz plots, one can resolve all the difficulties and cleanly extract weak phases. In this talk I describe how this is done, and present preliminary results on the measurement of gamma using the decays B -> K pi pi and B -> K Kbar K.