I rarely link outside of this blog, but I ran across a post about an artist creating a map of NY City from scrap-paper sketches drawn by strangers when he asks for directions. See more here.
There are so many aspects of this that appeal to me. People whip out smartphones, and the artist asks for a hand-drawn version. People reveal how they make sense of space, what the landmarks are, and how they navigate. A mosaic of discrete pieces makes a weird whole (in which there are probably weird holes). It's another form of cartography. And so on. Map geeks rejoice.