Future cosmology space missions will concentrate on measuring the
polarization of the Cosmic Microwave Background (CMB), which potentially
carries invaluable information about the earliest phases of the evolution
of our universe. Such ambitious projects will ultimately be limited by
the sensitivity of the instrument and by the accuracy at which
polarized foreground emission from our own Galaxy can be subtracted
out. We present the PILOT balloon project which will aim at
characterizing one of these foreground sources, the polarization of
the dust continuum emission in the diffuse interstellar medium. The
PILOT experiment will also constitute a test-bed for using
multiplexed bolometer arrays for polarization measurements.