Abstract : The pentagram map and its analogs act on interesting and complicated spaces. The simplest of them is the classical moduli space $M_{0,n}$ of rational curves of genus $0$. These moduli spaces have a rich combinatorial structure related to the notion of "Coxeter frieze pattern" and can be understood as a "cluster manifolds". In this talk, I will explain how to describe the action of the pentagram map (and its analogs) in terms of friezes. The main goal is to understand how does this action fit with the cluster algebra structure, in particular, with the canonical (pre)symplectic form.