Measurements of sin2alpha/phi2 from B -> pipi, rhopi and rhorho modes
  B meson decays involving b -> u transitions are sensitive to the unitarity triangle angle alpha (or phi2). The BaBar and Belle experiments have studied B-meson decays to pipi, rhopi and rhorho final states. It is possible to combine these measurements to constrain alpha with a precision of O(10 degrees) and a central value of approximately 100 degrees. These results are consistent with Standard Model expectations. 
A. Bevan (for the BaBar collaboration)