  We measure the branching fraction, polarization and CP asymmetry of B+ ->
rho+rho0 decays and search for the decay B+ -> rho+f_0(980) based on a data
sample of 231.8 million Y(4S)->BB decays collected with the BaBar detector at
the SLAC PEP-II asymmetric-energy B factory. In B+ -> rho+rho0 decays we
measure B=(16.8+-2.2+-2.3)x10-6, f_L=0.905+-0.042+0.023-0.027, and
A_CP=-0.12+-0.13+-0.10, and find an upper limit on the branching fraction of B+
-> rho+f_0(980)(->pi+pi-) of 1.9x10-6 at 90% Confidence Level.
