Pressing question that could end all conspiracy theories (or prove them)
Cell phone calls
There were several calls that day reportedly from cell phones and seat back phones. It is possible from these calls to determine the EXACT place each plane was at any given time. This could end several discrepancies as to what time flight 77 hit the Pentagon (the time varies depending on what source you read). It could give the EXACT path of all flights, as the transpoder codes were turned off, this has been somewhat of a grey area, especially for flights 93 and 77. Most phones toiday are of the technology CDMA. In this technology the cell phone may "talk" to several gound stations (cell sites) at one time. Using triangulation, these calls can be pinpointed. With several calls happening at different times, this could provide very useful info. It must be noted here, that the calls themselves are not recorded, but the time stamp, date, phone #, and electronic serial number (or ESN) of the phone is (for billing and other purposes). This applies to CDMA phones (the most common in the US), but also applies to many other types. I do not know if the same applies to the seatback phones or not, but I would imagine that something similar is in place. The calls information (for cell phones) are required by the FCC to be backed up, or reside in the "switch" at a local office for 3-5 years. (I forget the exact time, i believe the FCC may have changed it lately).
This could be a major breaking point in finding out what happened. It would end discrepancies and theories such as plane swapping, remote control and the idea that some of the calls were faked or did not happen.