In playing the CNN video below I noticed that it looked like a real video, and not 5 frames together as has been said. Several sites have put these 5 frames together and made a moving .gif file, or other type video to show it in motion.
The problem is on the CNN video, it appeared to be more than 5 frames.
I don't know where the "5 frames" story came from, but that has been the accepted story. (if anyone finds the original story of it saying "5 frames" please post in the comments.

Here is the CNN video... (hit play video)
http://www.cnn.com/2002/US/03/07/gen.pentagon.pictures/index.html

Here it is framed out....
http://fakepentagoncamera.batcave.net/
clearly more than 5 frames.
Does someone want to call CNN and ask them where they got the additional frames?

here are some other good analysis of this "fake" video
http://website.lineone.net/~bosankoe/analysis.htm
http://thewebfairy.com/911/pentagon/multiframes.htm
http://thewebfairy.com/911/pentagon/
Brad