I was also into caving. I used to go to these elaborate caves in different places. Carlsbad is pretty good. There are several good spots in Colorado too.
Know what I used to do? I had this special stuff I squirted on walls that glowed. I'd make different marks for places I had been, to indicate the direction of the exit, to indicate hazardous areas and so on.
Most cavers do this. Sometimes we used unique symbols, but some were "universally understood" too. I'm rambling...
What I'd like to see in Skyrim is .... Chalk. Yep. Chalk.
I'd like to be able to mark the walls of a cave in the game with a symbol or series of symbols so that I understood where I had been, where I still needed to explore, where there's a trap, and which way is out, among other things.
I don't even care if it's just a small dot on the cave wall that can be clearly seen. If I can leave one, two, or three dots next to each other, I can understand what they mean and use them as I see fit. If they're different colors that works too. Bonus if it adds a mark to that spot on my map in the game.
Yep. Not a real complicated idea. Simple actually...
But some of the dungeons in Oblivion and the expansions were massive. I imagine that there will be even larger dungeons in Skyrim. Some of them can get VERY confusing.
A little chalk would go a long way.