Follow the principle of WikiBrainMapping but this time facilitate physical exploration by rather than relying on the knowledge of the brain, rely on the knowledge of a physical area, e.g. a city.
The key advantage being to leverage the very powerful geospatial memory acquired through trips.
The result could be either printed to facilitate carrying around and easy modification or used on a mobile device to allow for simple position tracking (cf Overlay).
Watching a Starcraft II replay and having to remember the structure of the map without having physically explored it first, unlike the equivalent in a first-person shooter.