  We consider worldsheet correlation functions for strings in AdS_5 x S^5 using
a light-cone gauge for the worldsheet theory. We compute the saddle-point
approximation to three-point functions of BMN vertex operators, all with large
charges, by explicitly finding the intersection of three euclidean BMN strings.
We repeat this calculation for non-BPS circular winding strings extended along
a great circle of the S^5, though in this case the appropriate form of the
vertex operator is uncertain. Furthermore, we compute the spectrum of
fluctuations about euclidean BMN strings for generic boundary conditions, and
show that the spectrum depends only on the total charge and not the details of
the string configuration. We extend our considerations to include near-BMN
vertex operators and through the evaluation of the string path integral make
contact with the light-cone string field theory calculations of gauge theory
three-point structure constants.
