Density Fluctuations in the Galactic Halo and Experimental Searches for   Dark Matter
  Clumping of elementary dark matter in the Galaxy halo may be inevitable. If so, the nondetection of certain dark matter candidates could simply mean that the local halo density is low. Conversely, indirect detection of annihilation products could be facilitated, perhaps to an embarrassing degree. 
Ira Wasserman (Cornell U.)