  Gravitational collapse is one of the most striking phenomena in gravitational
physics. The cosmic censorship conjecture has provided strong motivation for
researches in this field. In the absence of general proof for the censorship,
many examples have been proposed, in which naked singularity is the outcome of
gravitational collapse. Recent development has revealed that there are examples
of naked singularity formation in the collapse of physically reasonable matter
fields, although the stability of these examples is still uncertain. We propose
the concept of ``effective naked singularities'', which will be quite helpful
because general relativity has the limitation of its application for
high-energy end. The appearance of naked singularities is not detestable but
can open a window for new physics of strongly curved spacetimes.
