  Many lens surveys have hitherto used observations of large samples of
background sources to select the small minority which are multiply imaged by
lensing galaxies along the line of sight. Recently surveys such as SLACS and
OLS have improved the efficiency of surveys by pre-selecting double-redshift
systems from SDSS. We explore other ways to improve survey efficiency by
optimum use of astrometric and morphological information in existing
large-scale optical and radio surveys. The method exploits the small position
differences between FIRST radio positions of lensed images and the SDSS lens
galaxy positions, together with the marginal resolution of some larger
gravitational lens systems by the FIRST beam. We present results of a small
pilot study with the VLA and MERLIN, and discuss the desirable criteria for
future surveys.
