  We investigate threshold pion photoproduction in the framework of heavy
baryon chiral perturbation theory. We give the expansion of the electric dipole
amplitude $E_{0+}$ to three orders in $\mu$, the ratio of the pion to nucleon
mass, and show that it is slowly converging. We argue that this observable is
not a good testing ground for the chiral dynamics of QCD. In contrast, we
exhibit new and fastly converging low--energy theorems in the P--waves which
should be used to constrain the data analysis. We also discuss the importance
of polarization observables to accurately pin down certain multipoles and give
predictions for the reaction $\gamma n \to \pi^0 n$.
