I know I've read different folks comment on how they hate post play narratives and don't read them. I don't understand this, because as a DM that's really the only place I get to see other DMs at work. It's the closest thing we have to a shared corpus of play data to explore and experiment with.
After the SoCalMini Con I thought about how it would be cool if I could, not just tell you about the events, but show you where the party went in the dungeon. I didn't end up doing it because it would have taken a lot of work (and thus it's probably a no go from the start). But the idea was to show you the dungeon map and then the party's movements on that map through time, animated.
I don't think heat map is the right term but it would be related. The session I have in mind had a lot of backtracking and circling, so I thought I might draw a line showing the party's progress and decay the color as they crossed and recrossed their own path. Maybe show the most recent location of the party in a nice orange and turn it to a gray or brown as the animation progresses.
Why do that? Well, we have modules we share in common-- B1, B2, Tomb of Horrors, Caverns of Thracia, all get a lot of mention on blogs and seem popular at tournaments. What if you could look, literally look, at how 20 different parties ran through B1? You might see, "They always turn left here," or, "This intersection always causes confusion."
I know, unless someone makes an app that would do the animation after we just punch in room numbers, this will never happen. But maybe, if we had a kind of conventional way to note party movement we could still share the data. I'm thinking something like:
2 > 4 > . > 2
where the numbers are rooms and the "." is a pause of a turn or so (to show confusion or decision making). I suppose that wouldn't capture a lot of corridor exploration. I know that as a player I tend to try and get the lay of the land before I open any doors. Oh well, it's a thought.