  I review the progress made on the physics of black hole systems in the
context of the analogy between AGN and microquasars that was proposed one
decade ago. If the emerging empirical correlations between the observational
properties of stellar and supermassive black holes will become more robust, we
will use them to determine the mass and spin of black holes, independently of
theoretical models. Microquasars are fossils of sources of Gamma-ray bursts
(GRBs) of long duration, and their kinematics provides observational clues on
the physics of collapsars. If jets in GRBs, microquasars and AGN are due to a
unique universal magnetohydrodynamic mechanism, synergy between the research on
these three different classes of cosmic objects will lead to further progress
in black hole physics and astrophysics.
  The potential contributions with INTEGRAL in this field of research are also
discussed. It is shown that the Galactic Plane Survey (GPS) with INTEGRAL is
unraveling new extragalactic sources of hard x-rays behind the Milky Way, as
well as new black hole high-mass binaries that were hidden by large columns of
gas and dust.
