Abstract: We quantitatively relate the Patterson-Sullivant currents to the asymmetric Lipschitz metric on Outer space and to Guirardel's intersection number. As an application we show that for any N\ge 2 there exists a positive constant C_N>0 such that for every \phi\in Out(F_N), where F_N=F(A)=F(a_1,..,a_N) is the free group of rank N, we have $C_N\le \lambda_A(\phi)/ \Lambda_A(\phi) \le 1$. Here $\Lambda_A(\phi)= \sup_{w\ne 1} ||\phi(w)||_A/||w||_A$ is the "extremal distortion" of $\phi$, and $\lambda_A(\phi)$ is the "generic stretching factor" of $\phi$, that is, $\lambda_A(\phi)$ is the asymptotic distortion $||\phi(w)||_A/||w||_A$ where $w$ is a "long random element" in $F(A)$, as $||w||_A\to\infty$. The talk is based on joint work with Martin Lustig.