Imagine the Manhattan street grid took over the world.Gotham-phile geocachers and assorted other place-nerds, now you can give your location relative to the Manhattan grid. For instance, I'm at S 507th St and 15441st Avenue (it gets worse, a point in northern Uzbekistan features all the avenues converging, a point off the coast of western Australia has First Street and what I'd call "Opposite Avenue", and the other all-avenues converge is in the southeast Pacific a thousand miles off Chile.)
Have fun, folks. Somewhat less fun for those who are actually IN New York...