Well, I don't know that I'd call Snopes ever-reliable. However, it does have a plausible explanation for the wings that I hadn't seen before:

Quote:
As the front of the Boeing 757 hit the Pentagon, the outer portions of the wings likely snapped during the initial impact, then were pushed inward towards the fuselage and carried into the building's interior; the inner portions of the wings probably penetrated the Pentagon walls with the rest of the plane. Any sizable portions of the wings were destroyed in the explosion or the subsequent fire.

It also shows a picture of what they claim to be wing damage to the Pentagon, which shows, essentially, the building's fascia scorched and blackened on either side of the impact point. If you assume that the wings did mostly snap off, it's possible that there was an immediate explosion of the fuel in the wings that disintegrated them. And I suppose it's possible that an engine could have gone in with the plane.

To be honest, both Snopes' theory and the not-a-plane theory are a little too convenient and hopeful of coincidence. However, given that we know other planes definitely did hit buildings that day in similar ways....

I still don't know what that tiny thing is in the first frame of the Pentagon time-delay camera.