Because I'm just an amateur, I've never really engaged with the concept of Kleinian groups before, so I'm only just starting with elementary concepts. So I have a couple of really basic questions. I think I read that all the finite spherical groups (including the symmetry groups of all polyhedra) occur as Kleinian groups. Is that correct? If so, is it because PSL(2,C) has a subgroup that is equivalent to the rotation group of a sphere? Are any _other_ finite groups Kleinian? That is, is there a finite Kleinian group that is _not_ the symmetry group of a polyhedron? (When I say "is", I hope it's clear that I mean "is isomorphic to". When I say "finite", I mean a finite number of elements, not the concept of "geometrically finite" that I haven't yet wrapped my head around in the context of Kleinian groups.)