  We use a cosmological simulation of the Local Group to make quantitative and
speculative predictions for direct detection experiments. Cold dark matter
(CDM) halos form via a complex series of mergers, accretion events and violent
relaxation which precludes the formation of significant caustic features
predicted by axially symmetric collapse. The halo density profiles are combined
with observational constraints on the galactic mass distribution to constrain
the local density of cold dark matter to lie in the range 0.18 <~
rho_CDM(R_solar)/GeV cm^-3 <~ 0.30. In velocity space, coherent streams of dark
matter from tidally disrupted halos fill the halo and provide a tracer of the
merging hierarchy. The particle velocities within triaxial CDM halos cannot be
approximated by a simple Maxwellian distribution and is radially biased at the
solar position. The detailed phase space structure within the solar system will
depend on the early merger history of the progenitor halos and the importance
of major mergers over accretion dominated growth. We follow the formation of a
``Draco'' sized dSph halo of mass 10^8M_solar with several million particles
and high force accuracy. Its internal structure and substructure resembles that
of galactic or cluster mass halos: the density profile has a singular central
cusp and it contains thousands of sub-halos orbiting within its virial radius
demonstrating a self-similar nature to collisionless dark matter
sub-clustering. The singular cores of substructure halos always survive
complete tidal disruption although mass loss is continuous and rapid.
Extrapolating wildly to earth mass halos with velocity dispersion of 1 m s^-1
(roughly equal to the free streaming scale for neutralinos) we find that most
of the dark matter may remain attached to bound subhalos. (Abridged)
