We received the two photos you see here from viewer Buddy Howard, who noticed a small circular spot in the second image (upper left, just above the cloud edge) and a larger one in the first. He hadn't noticed anything in the sky when he shot the pictures, and was surprised to see them there later on. He checked with us to see if we had any ideas as to what it might be, and i think we do.
He had already ruled out the idea that the sun or moon was showing up behind a cloud or through some haze, and that there wasn't some kind of spotlight shining in the area that create so perfectly round an image. He also said that it was not raining at the time, although there may have been some earlier judging from the clouds and the general weather situation that day.
My guess is he caught some kind of very small object close to the camera that was largely unnoticeable in the dim light of the evening, and with the camera focused far away on the sky, the object (a large piece of dust, a gnat, perhaps a drop of water blow off one of the trees, etc) was illuminated by the flash when it went off, but was close enough to the camera to show up as a totally unfocused circle of light. Small compact cameras with a flash that sits close to the lens are especially prone to pick up these kinds of backscattered images, and I can remember getting some of these from time to time with a compact underwater camera I used on some scuba diving excursions. There would be a small amount of silt in the water that I would not even notice, but due to the close lens-flash distance, it was enough to produce sizable diamond-shaped "spots" on some of the images (diamond shaped because that was the shape of the iris in that camera's lens). So, Buddy seems to have picked up some small object that was lit by his flash and left behind the "orb" you see in his shots.
For more examples of such orbs, see the article I linked to at Wikipedia.