  We present a new way of looking at the very long term evolution of GRBs in
which the disk of material surrounding the putative black hole powering the GRB
jet modulates the mass flow, and hence the efficacy of the process that
extracts rotational energy from the black hole and inner accretion disk. The
pre-Swift paradigm of achromatic, shallow-to-steep "breaks" in the long term
GRB light curves has not been borne out by detailed Swift data amassed in the
past several years. We argue that, given the initial existence of a fall-back
disk near the progenitor, an unavoidable consequence will be the formation of
an "external disk" whose outer edge continually moves to larger radii due to
angular momentum transport and lack of a confining torque. The mass reservoir
at large radii moves outward with time and gives a natural power law decay to
the GRB light curves. In this model, the different canonical power law decay
segments in the GRB identified by Zhang et al. and Nousek et al. represent
different physical states of the accretion disk. We identify a physical disk
state with each power law segment.
