  A long-standing problem in astrophysics is to measure the mass associated
with galaxies. Gravitational lensing provides one of the cleanest ways to make
this measurement. To date, the most powerful lensing probes of galactic mass
have been multiply imaged QSO's (strong lensing of a background point source)
and galaxy-galaxy lensing (weak deformation of many background galaxies). Here
we point out that the mass associated with galaxies also lenses the Cosmic
Microwave Background (CMB) and this effect is potentially detectable in small
scale experiments. The signal is small (roughly a few tenths of a microKelvin)
but has a characteristic shape and extends out well beyond the visible region
of the galaxy.
