  We present some results on the study of stellar population properties and
distances of galaxies using the SBF technique. The applications summarized here
show that the Surface Brightness Fluctuations (SBF) method is able to i)
provide accurate distances of resolved and unresolved stellar systems from ~10
Kpc to ~150 Mpc, and ii) to reliably constrain the physical properties (e.g.
age and metallicity) of unresolved stellar systems.
