  A simple mid-infrared-to-optical color criterion of R-[24]>14 Vega mag
results in a robust selection of approximately half of the redshift 2
ultraluminous infrared galaxy (ULIRG) population. These `Dust-Obscured
Galaxies', or DOGs, have many properties that suggest that they are good
candidates for systems in a transition phase between gas-rich mergers and QSOs.
