Limits to galaxy mass distribution from galaxy-galaxy lensing.

The average gravitational lens distortion of background galaxy images by foreground galaxies in an independent, non-kinematical measurement of average galaxy mass distribution M(r)/r. The method does not require spectroscopic detectability or virial or orbital assumptions and is applicable to galaxies of all types. I review here the progress to date of an automated survey of the coherent gravitational lens distortion of the images of 47,000 background galaxies around 12,000 foreground galaxies.