Reply #21: yes, I've seen something like this...

[amazona]

...was it perfectly round? I have seen some weather balloons that are perfectly round and would really make you stop and think if you didn't know they were coming. Your description does sound like a balloon to me. They are silent and can be quite eerie if they are high up.

I have also seen light reflection off the bellies of migrating geese, which looks like a formation of oval-shaped (not circular) saucers flying in a V. That is not what you saw, but it is just an example of something that really looks nifty and which at first I thought was a UFO. However, geese are not silent, either, and when I heard them "talking," I snapped to a realization of what I was seeing.

Where do you live? Some areas have a lot more UFO activity than others. I'm a bit chicken, I try to avoid areas that are experiencing too much activity, but maybe one day I will get up my nerve and see the real thing!