  We review the current status of QSO clustering measurements, particular with
respect to their relevance in understanding AGN physics. Measurements based on
the 2dF QSO Redshift Survey (2QZ) find a scale length for QSO clustering of
s_0=5.76(+0.17-0.27) h-1 Mpc at a redshift <z>~1.5, very similar to low
redshift galaxies. There is no evidence of evolution in the clustering of QSOs
from z~0.5 to z~2.2. This lack of evolution and low clustering amplitude
suggests a short life time for AGN activity of the order ~10^6-10^7 years.
Large surveys such at the 2QZ and SDSS also allow the the study of QSO
environments in 3D for the first time (at least at low redshift), early results
from this work seem to show no difference between the environments of QSOs and
normal galaxies. Future studies e.g. measuring clustering as a function of
black hole mass, and deep QSO surveys should provide further insight into the
formation and evolution of AGN.
