  We introduce the Working Group 2 proceedings contributions from the 2nd
workshop on the CKM Unitarity Triangle and note their connection to the
proceedings of the first workshop. The topic of WG2 was the determination of
the CKM matrix elements Vtd and Vts from B-Bbar mixing, radiative penguin B to
X{s/d} gamma decays and rare (semi)leptonic decays such as B to Xs l+ l-.
