I've never seen a UFO. However, recently I saw something a bit odd. Actually, I saw the same phenomena twice in one week. I have no idea what caused it - there doesn't seem to be an obvious explanation. I wish I had a camera with me at the time [NOTE: the attached picture is simply a photo of contrails I found on the internet]. Perhaps I'll get another opportunity to take a picture. The following is a summary of what I saw during both occasions.
I saw a well defined contrail of a jet that made a straight line across the sky. I did not see the jet which created this contrail. Near the contrail was a cloud. The contrail did NOT intersect or touch the cloud. The cloud had a clear "cut" directly through it - the cut was aligned parallel to the contrail of the jet. The "cut" was perfectly straight, not very wide, and through it you could see blue sky. As I watched this cut for the next 3 or 4 minutes, it slowly dissipated - and was filled in by the surrounding cloud (via wind and natural motion of the air). The contrail of the jet remained in the sky, but appeared to be moving/dissipating at the same rate as the cloud. I do not see how the cut in the cloud could have possibly been formed by the jet. Like I said, the contrail did not intersect the cloud, and the breeze was shifting the contrail and the cloud at the same rate.
Has anyone seen a similar phenomena? I have no idea what caused it - but it reminds me of a few witness accounts of the O'Hare Airport UFO sighting in 2006. Witnesses claimed to see a UFO hovering above the airport - after a few minutes, the UFO sped up through the cloud layer and left a gaping hole. The hole then closed within a few minutes.
Maybe this is nothing at all. I just wanted to put it out there.
Information regarding the O'Hare Airport sighting: