I love pictograms and symbols and trying to convey meaning in its simplest form. And I always loved the idea of the danger room for heroes, because, well it's a lot like exploring a dungeon-- you don't know what to expect. Also, you can play it solo.
I think Zak posted a random danger room generator in the last few months. I know I made one for DC Heroes years ago, but I'd have to dig it out because I don't remember anything about that attempt. Anyway, what if you took the hexagonal geomorphs I've been posting, throw in a plethora of cool hazard symbols: