In this paper, Guilherme França and André LeClair show that $$\gamma_{y}\sim 2 \pi \left(y-11/8\right)/W\left((y-11/8)e^{-1}\right)$$ where $W$ is the Lambert W function, and $\gamma_{y}$ is the imaginary part of the the $y$th non-trivial zero along the critical line. This formula can then be used in a similar way to Gram points for finding zeta zeros. (Of course, as GH from MO pointed out below, this only applies to the zeros on the critical line.)