  This note which can be viewed as a complement to Alex Postnikov's paper
math.CO/0507163, presents a self-contained overview of basic properties of
nested complexes and their two dual polyhedral realizations: as complete
simplicial fans, and as simple polytopes. Most of the results are not new; our
aim is to bring into focus a striking similarity between nested complexes and
associated fans and polytopes on one side, and cluster complexes and
generalized associahedra introduced and studied in hep-th/0111053,
math.CO/0202004, on the other side.
