Quite a long time ago, RPGNet user Gullerbutry had a wonderful thread on "triangle tables". I turned around and made a set of triangle tables for random exploration of a post-apocalypse city or its environs. I was straightening out some documents and assets and, even though I linked to them a long time ago on Dreams of Flesh and Spirit, I thought I'd put them up on here as well.
The way these tables work (you can see a sample image below) is you roll 5dF and cross index the + results and the - results. The little numbers in the corners show you the probability for that square (that's how I figured out the distribution). For these tables, you either decide what type of area is being explored or roll on Table 1. Then you find the appropriate table and roll again. The goal is to figure out what there is for exploration within two rolls or so.