I really like an idea a friend of mine had. You know how road maps have a city index that lists the grid block the city is located in? With letters across the side and numbers across the top, chicago would be listed in C-5 (or whatever). The map board for "on the underground" actually uses this.
As for myself, when playing OtU I found I was finding the cities a lot faster once I stopped using the coordinates and just started glancing at the picture on each card! Likewise, I never have a problem with the TtR tickets - except these Switzerland ones that don't actually show you where the city is at all, ugh.