  We present a statistical study of the detectability of lightcurves of Kuiper
Belt objects (KBOs). Some Kuiper Belt objects display lightcurves that appear
"flat", i.e., there are no significant brightness variations within the
photometric uncertainties. Under the assumption that KBO lightcurves are mainly
due to shape, the lack of brightness variations may be due to (1) the objects
have very nearly spherical shapes, or (2) their rotation axes coincide with the
line of sight. We investigate the relative importance of these two effects and
relate it to the observed fraction of "flat" lightcurves. This study suggests
that the fraction of KBOs with detectable brightness variations may provide
clues about the shape distribution of these objects. Although the current
database of rotational properties of KBOs is still insufficient to draw any
statistically meaningful conclusions, we expect that, with a larger dataset,
this method will provide a useful test for candidate KBO shape distributions.
