  We present branching fraction measurements for the radiative decays B+ ->
rho+ gamma, B0 -> rho0 gamma, and B0 -> omega gamma. The analysis is based on a
data sample of 465 million BBbar events collected with the BaBar detector at
the PEP-II asymmetric B factory. We find BR(B+ -> rho+ gamma) = (1.20 +0.42
-0.37 +/-0.20) x 10^-6, BR(B0 -> rho0 gamma) = (0.97 +0.24 -0.22 +/-0.06) x
10^-6, and a 90% C.L. upper limit BR(B0 -> omega gamma) < 0.9 x 10^-6, where
the first error is statistical and the second is systematic. We also measure
the isospin-violating quantities Gamma(B+ -> rho+ gamma) / 2Gamma(B0 -> rho0
gamma) - 1 = -0.43 +0.25 -0.22 +/-0.10.
