  Gravitational lensing has seen a surge of interest in the past few years. The
handful of strong lensing systems known in the year 2000 has now been replaced
with hundreds, thanks to innovative multi-wavelength selection, and there is an
imminent prospect of thousands of lenses from Herschel and other sub-millimetre
surveys. Euclid and the Square Kilometre Array promise tens or even hundreds of
thousands. Gravitational lensing is one of the very few probes capable of
mapping dark matter halo distributions. Lensing also provides independent
cosmological parameter estimates and enables the study of galaxy populations
that are otherwise too faint for detailed study. SALT is extremely well placed
to have an enormous impact with follow-up observations of foreground lenses and
background sources from e.g. Herschel, the South Pole Telescope, the Atacama
Cosmology Telescope, Euclid and the Square Kilometre Array. This paper reviews
the prospects for high-impact SALT science and the many constraints of galaxy
evolution that can result.
