>>1126511I admit what I said wasn't entirely accurate, actually. I was mixing up and combining different things. One thing is that you can use a soft cloth to literally wipe up the early morning dew from plants / rocks, etc and then wring the moisture out of the cloth.
The other thing, what I was actually thinking of, is called a solar still. You basically dig a hole down to where the soil becomes somewhat moist (even in the desert you only have to dig a few feet down, sometimes easier said than done in the hard earth), put a container in the middle, stretch a plastic sheet over it, and put a small rock or other weight in the center. Moisture evaporates up out of the earth, condenses on the sheet, runs down and drips into the cup. If you have a long straw of bit of plastic tube you can suck the water out without having to dismantle the still to get to the cup.
You can also extract moisture out of plant matter this way by putting leaves and such in the put with the cup.