  We present the completed results of a high resolution radio imaging survey of
all (~200) low-luminosity active galactic nuclei (LLAGNs) and AGNs in the
Palomar Spectroscopic Sample. The high incidences of pc-scale radio nuclei,
with T(brightness) >=10^7 K, and sub-parsec jets argue for accreting black
holes in >=50% of all LINERs and low-luminosity Seyferts; there is no evidence
against all LLAGNs being mini-AGNs. The radio luminosity function (RLF) of
Palomar Sample LLAGNs and AGNs extends three orders of magnitude below, and is
continuous with, that of `classical' AGNs. We find marginal evidence for a
low-power turnover in the RLF; nevertheless LLAGNs are responsible for a
significant fraction of present day mass accretion. Adopting the jet model of
Falcke & Biermann, we show that the accretion energy output in LLAGNs is
dominated by the energy in the observed jets rather than the radiated
bolometric luminosity. The Palomar LLAGNs and AGNs follow the same scaling
between jet power and narrow line region (NLR) luminosity as the pc to kpc jets
in powerful radio galaxies. Eddington ratios of <= 10^{-1} - 10^{-5} are
implied in jet models of the radio emission. We find evidence that, in analogy
to Galactic black hole candidates, LINERs are in a `low/hard' state (gas poor
nuclei, low Eddington ratio, ability to launch collimated jets) while
low-luminosity Seyferts are in a `high' state (gas rich nuclei, higher
Eddington ratio, less likely to launch collimated jets). The jets are
energetically more significant than supernovae in the LLAGN host galaxies, and
are potentially able to deposit sufficient energy into the innermost parsecs to
significantly slow the gas supply to the accretion disk.
