In this talk I'll explore one example of a topological field theory, the "string topology" of Chas-Sullivan. I will give a definition of A_\infty Frobenius that is good enough to accept the cochain algebra of a Poincare duality space and produce, using the machinery of Kevin Costello, a topological conformal field theory whose closed string state space is the space of (integer) chains on the free loop space. This talk is joint work (in progress) with Jacob Lurie, and owes a great deal to the work and influence of Kevin Costello.