  We consider super-critical accretion with angular momentum onto stellar-mass
black holes as a possible mechanism for growing billion-solar-mass holes from
light seeds at early times. We use the radiatively-inefficient "slim disk"
solution -- advective, optically thick flows that generalize the standard
geometrically thin disk model -- to show how mildly super-Eddington
intermittent accretion may significantly ease the problem of assembling the
first massive black holes when the Universe was less than 0.8 Gyr old. Because
of the low radiative efficiencies of slim disks around non-rotating as well as
rapidly rotating holes, the mass e-folding timescale in this regime is nearly
independent of the spin parameter. The conditions that may lead to
super-critical growth in the early Universe are briefly discussed.
