Consider a punctured surface Σ, with (necessarily free) fundamental group Fn. A very basic connection between MCG(Σ) and Out(Fn) is provided by considering the action of a mapping class on the level of fundamental groups. I will discuss recent joint work with E. Bering and Y. Qing where we provide an algorithm to answer the following notably open question: Given an automorphism φ of Fn, is φ induced by a surface homeomorphism? Stated simply, "Is φ geometric?"