Well at this point we have all the people who got phone calls from pasengers before they said "Let's Roll" and took down the plane - which COULD be a coverup, as I don't know any of those people, or have an easy way to confirm their story on one hand. On the other hand we ahve Rummy saying something that doesn't entirely make sense, except maybe as Secretary of Defense he's always thinking about shooting things down, has it on the brain so bad that it just slips out when talking about things crashing for other reasons.
It really isn't much of a basis for a conspiracy, unless you are the sort of person who says Art Bell callers get a bad rap (HI RANXER!!!

) As for the one that hit the Pentagon, I saw some flash video saying it was shot down as well, and that a missle is what hit the Pentagon based on various video footages, a lack of debris, skid marks, etc, but I've not heard of any serious investigation of this, and so I could have saved this thread a lot of time by saying
OMG WTF CONSPIRACY!!!