  In this paper we show how to produce a large number of representations of a
graph C*-algebra in the space of the bounded linear operators in $L^2(X,\mu)$.
These representations are very concrete and, in the case of graphs that satisfy
condition (K), we use our techniques to realize the associated graph C*-algebra
as a subalgebra of the bounded operators in $L^2(R)$. We also show how to
describe some Perron-Frobenius operators in $L^1(X,\mu)$, in terms of the
representations we associate to a graph.
