  The latest results of the QUEST survey for RR Lyrae stars are described. This
survey, which is designed to find and characterize sub-structures in the halo
of our Galaxy, has covered about 700 square degrees of the sky and has detected
693 RR Lyrae stars, most of which are new discoveries. The spatial distribution
of the RR Lyrae stars reveals several interesting groups in the halo. Some of
them appear to be related to previous detections of the destruction of dwarf
spheroidal galaxies (the Sagittarius tidal streams, the Virgo stellar stream,
the Monoceros ring) or globular clusters (Palomar 5), while others still have
an unknown origin.
