  We discuss nontrivial examples illustrating that perturbative gravity is in
some sense the `square' of gauge theory. This statement can be made precise at
tree-level using the Kawai, Lewellen and Tye relations between open and closed
string tree amplitudes. These relations, when combined with modern methods for
computing amplitudes, allow us to obtain loop-level relations, and thereby new
supergravity loop amplitudes. The amplitudes show that N=8 supergravity is less
ultraviolet divergent than previously thought. As a different application, we
show that the collinear splitting amplitudes of gravity are essentially squares
of the corresponding ones in QCD.
