  Lattice Monte Carlo simulations now include the effects of 2 light sea quarks
and 1 strange sea quark through the use of an improved staggered fermion
action. Consequently, results important to phenomenology are free of the
approximate 10% errors inherent in the quenched approximation. This talk
reports on calculations of the B and Bs decay constants and B -> pi l nu form
factors. Accurate determinations of these quantities will lead to tighter
constraints on CKM matrix elements.
