  The power spectrum of mass density fluctuations is evaluated from the Mark
III and the SFI catalogs of peculiar velocities by a maximum likelihood
analysis, using parametric models for the power spectrum and for the errors.
The applications to the two different data sets, using generalized CDM models
with and without COBE normalization, give consistent results. The general
result is a relatively high amplitude of the power spectrum, with \sigma_8
\Omega_m^{0.6} = 0.8+/-0.2 at 90% confidence. Casting the results in the
\Omega_m - \Omega_\Lambda plane, yields complementary constraints to those of
the high-redshift supernovae, together favoring a nearly flat, unbound and
accelerating universe with comparable contributions from \Omega_m and
\Omega_\Lambda. Further implications on the cosmological parameters, arising
from a joint analysis of the velocities together with small-scale CMB
anisotropies and the high-redshift supernovae, are also briefly described.
