I'm not qualified to comment on the general usefulness of solar stills- I've never tried to use one, so I'll stay away from that issue (the East generally has more water than sunlight). I will just say that it was my impression that it was important to use clear plastic, in order to take advantage of the greenhouse effect- the idea is for the air and moisture inside the pit to heat, not the plastic itself, which after all is the condensing surface, so I would think the clearer the better. I was also under the impresson that part of the idea was to fill the pit with moisture-containing vegetation, bad water, urine, whatever is available- I never had the impression that much water was expected from the soil itself.<br><br>I do remember that in "The Complete Walker III" Colin Fletcher mentioned some plastic that was supposed to be better than most, and I remember seeing ads in Backpacker magazine for that plastic shortly after the edition came out. I can look it up if there's any interest.<br><br><br>