  The formation and growth of supermassive black holes is a key issue to unveil
the secrets of galaxy formation. In particular, the gravitational recoil
produced in the merger of unequal mass black hole binaries could have a number
of astrophysical implications, such as the ejection of black holes from the
host galaxy or globular cluster. We present estimates of the recoil velocity
that include the effect of small eccentricities. The approach is specially
suited for the last stage of the merger, where most of the emission of linear
momentum in gravitational waves takes place. Supplementing our estimates with
post-Newtonian approximations, we obtain lower and upper bounds that constrain
previous recoil velocities estimates as well as a best estimate that agrees
with numerical simulations in the quasi-circular case. For eccentricities e <=
0.1, the maximum recoil is found for mass ratios of M_1/M_2 ~ 0.38 with a best
estimate of ~ 167 (1 + e) km/s and upper and lower bounds of 79 (1 + e) km/s
and 216 (1 + e) km/s respectively.
