View the map from one angle and you'll see the streets. Tilt it and you see the neighbourhoods. Tilt it more and you see the bus and subway lines. I bought the Manhattan map a few years ago. Now there's a Second City version.
I find this map to be more entertaining than useful. Because it's a folding map, it's almost impossible to hold the entire map on the same plane. So I usually end up with each unfolded section of the map displaying a different function, and I can only examine one section at a time. Nice idea that doesn't work in practice.