  Here I summarize constraints on the nature of the dark matter halos of field
galaxies that have been obtained from the most recent investigations of (i)
weak galaxy-galaxy lensing and (ii) the dynamics of satellite galaxies in orbit
about large host galaxies. Both of these techniques are statistical in their in
their nature (i.e., large samples of galaxies are required to obtain a
"signal"), but since they have inherently different selection biases and
systematic errors they are quite complementary to each other. Results of work
over the last several years on weak lensing and satellite dynamics is revealing
a remarkably consistent picture regarding the dark matter halos of bright field
galaxies (L > L*). The halos extend to large physical radii (> 150 kpc/h) and
are flattened in projection on the sky, there is a marked difference in the
depths of the potential wells of early-type galaxies and late-type galaxies,
and the velocity dispersion profiles of the halos decrease at large projected
radii. All of these are expected to hold true in a cold dark matter universe
and, while neither technique can address the the possible small-scale conflicts
between CDM and observed galaxies, on scales > 50 kpc/h both techniques yield
results that are consistent with each other and with the predictions of CDM.
