QUOTE(GavinStrife @ Nov 20 2005, 11:29 AM) [snapback]940702[/snapback]
It was moving too fast to be an airplane at that height and not be able to be seen as an airplane
It looks *exactly* like a jet contrail. You would have difficulty seeing a plane at the leading tip of the contrail because you would only be seeing the shadowed underside of the craft. Remember that what you were seeing was at that moment flying over ground a significant distance from you, far enough for there to be an appreciable curvature of the earth between you and it. Combine that with the difficulty in judging the distance from one end and the other of the contrail due to its distance from you, plus the actual difference in angle between the plane's motion and you and the plane's motion and the ground directly beneath you, and it looks like the plane is falling when in actuality it is travelling horizontally, or at least tangentially, in relation to the ground.
Regarding how fast it was moving: you had time to look at it, call your friend from inside, watch for a while with the friend, go back inside to get your camera, come back, then take these pictures. A meteor going fast enough to experience compression burn would not have stayed in view long enough for you to have watched even for the first 10 seconds you said you watched when you first noticed it.
If the sky is clear tomorrow evening, I promise I'll take some pictures that look almost exactly like this and post them. Too late to do it today, plus we have low clouds, but we usually see "flocks" of these in the western twilit sky.