Well, the feds are trying to pass it off as an airliner. Odd, the only ones who have said that are the Pentagon and NASA. No way that THEY would have any motivation for giving that explanation...
My take: Somebody royally screwed up, and now the Pentagon is trying to cover its hindquarters. I've seen a LOT of planes flying - jet fighters, passenger planes, etc. That is either a missile or a small space launch.
You're all too conspiracy theory scared. It was a contrail from an American Airline passenger jet headed for Phoenix. Some Brit showed pictures taken from a couple of different angles to show how it looked from the side. Apparently the CBS picture's angle created an optical illusion. On the other hand it could have been aliens leaving Area 88.
I want a link to the pictures, first. I didn't see any links in the article I read, and that thing looks like a missile. Passenger liners do NOT leave a trail like that, nor does any military jet I've seen. And yes, I HAVE seen more than a few different military jets.