  We study the D-brane spectrum of N=2 string orbifold theories using the
boundary state formalism. The construction is carried out for orbifolds with
isolated singularities, non-isolated singularities and orbifolds with discrete
torsion. Our results agree with the corresponding K-theoretic predictions when
they are available and generalize them when they are not. This suggests that
the classification of boundary states provides a sort of "quantum K-theory"
just as chiral rings in CFT provide "quantum" generalizations of cohomology. We
discuss the identification of these states with D-branes wrapping holomorphic
cycles in the large radius limit of the CFT moduli space. The example C^3/Z_3
is worked out in full detail using local mirror symmetry techniques. We find a
precise correspondence between fractional branes at the orbifold point and
configurations of D-branes described by vector bundles on the exceptional P^2
cycle.
