I'm thinking of converting my CULT OF UNDEATH compression of the Carrion Crown adventure path by Paizo into, of all things, a hexcrawl. This will, of course, change significantly the way that the game will play and require a bit more work to be doable—but that's OK. In fact, I think it's desirable.
First things first, if I actually do this: I've added a hex overlay to my map. It doesn't have a key yet; but you can, of course, simply count. There are 26 columns across and 17 rows. While the rows don't necessarily line up (because they're hexes, not squares) if you count the columns first, going left to right, and then count down the second number, you'll get to the targeted hex. For example, Grozavest is located in 11:9; 11 hexes over from the left edge, and 9 hexes down from there. I'll probably eventually actually add numbers, but... no rush.