Here's some more evidence:
Maj. Douglas Rokke, PhD, U.S. Army (ret), former Director of the U.S. Army Depleted Uranium Project and 30-year veteran, had this to say about the explosion at the Pentagon on 9/11, "When you look at the whole thing, especially the crash site void of airplane parts, the size of the hole left in the building and the fact the projectile's impact penetrated numerous concrete walls, it looks like the work of a missile. And when you look at the damage, it was obviously a missile."
Or: Capt. Russ Wittenberg, U.S. Air Force, is a former U.S. Air Force fighter pilot with over 100 combat missions and a retired commercial pilot, who flew for Pan Am and United Airlines for 35 years.
According to Capt. Wittenberg, "The government story they handed us about 9/11 is total B.S., plain and simple."
In the 2007 documentary video, 9/11 Ripple Effect, he said "I flew the two actual aircraft which were involved in 9/11; the Fight number 175 and Flight 93, the 757 that allegedly went down in Shanksville and Flight 175 is the aircraft that's alleged to have hit the South Tower.
"I don't believe it's possible for, like I said, for a terrorist, a so-called terrorist, to train on a [Cessna] 172, then jump in a cockpit of a 757-767 class cockpit, and vertical navigate the aircraft, lateral navigate the aircraft, and fly the airplane at speeds exceeding its design limit speed by well over 100 knots, make high-speed high-banked turns, exceeding -- pulling probably 5, 6, 7 G's. And the aircraft would literally fall out of the sky. I couldn't do it and I'm absolutely positive they couldn't do it." 
Regarding Flight 77, which allegedly hit the Pentagon, Capt. Wittenberg said, "The airplane could not have flown at those speeds which they said it did without going into what they call a high speed stall. The airplane won't go that fast if you start pulling those high G maneuvers at those bank angles. ... To expect this alleged airplane to run these maneuvers with a total amateur at the controls is simply ludicrous ... It's roughly a 100 ton airplane. And an airplane that weighs 100 tons all assembled is still going to have 100 tons of disassembled trash and parts after it hits a building. There was no wreckage from a 757 at the Pentagon. ... The vehicle that hit the Pentagon was not Flight 77. We think, as you may have heard before, it was a cruise missile."
Or: Just a few dissenters, irrelevant?
Jan. 5, 2008 - Eight U.S. State Department Veterans Challenge Official Account of 9/11 - Official Account of 9/11: "Flawed", "Absurd", "Totally Inadequate", "a Cover-up" featured statements by:
* Daniel Ellsberg, PhD, former U.S. State Department envoy to Viet Nam and Special Assistant to the Assistant Secretary of Defense
* Col. Ann Wright, former Deputy Chief of Mission of U.S. Embassies in Sierra Leone, Micronesia and Afghanistan. 16 years as U.S. Diplomat. 29-year U.S. Army career.
* Fred Burks, former simultaneous interpreter for President Bill Clinton and George W. Bush and others. 18-year State Department career
* Melvin Goodman, PhD, former Senior Analyst, Bureau of Intelligence and Research, State Department. Later served as Division Chief, CIA's Office of Soviet Affairs and Professor of International Security, National War College
* Michael Springmann, retired career Foreign Service Officer. Former Consular Officer in Jeddah, Saudi Arabia. 20-year career with the State Department and the International Foreign Trade Administration, Commerce Department
* George Kenney, former career Foreign Service Officer. Served as Yugoslav desk officer at the State Department headquarters.
* Michael Mennard, PhD, retired career Foreign Service Officer. Served as Regional Public Affairs Officer in India
* Edward Peck, former Deputy Coordinator, Covert Intelligence Programs, U.S. State Department. Later served as Deputy Director of the White House Task Force on Terrorism under President Ronald Reagan. Former U.S. Ambassador and Chief of Mission in Iraq
Dec. 13, 2007 - Seven Senior Federal Engineers and Scientists Call for New 9/11 Investigation - Official Account of 9/11: "Impossible", "A Bunch of Hogwash", "Fatally Flawed" featured statements by:
* Lt. Col. Robert Bowman, PhD, Director of Advanced Space Programs Development under Presidents Gerald Ford and Jimmy Carter. Former Head of the Department of Aeronautical Engineering and Assistant Dean at the U.S. Air Force Institute of Technology
* David Griscom, PhD, Retired Research Physicist. Served 33 years at the Naval Research Laboratory in Washington, D.C.
* Joel Hirschhorn, PhD, Former Senior Staff Member, Congressional Office of Technology Assessment. Former Director of Environment, Energy and Natural Resources for the National Governors Association
* Enver Masud, MS, PE, Former Chief of the Strategic and Emergency Planning Branch, U.S. Department of Energy
* James Quintiere, PhD, Former Chief of the Fire Science Division of the National Institute of Standards and Technology (NIST)
* Dwain Deets, MS, Former Director, Aerospace Projects at NASA's Dryden Flight Research Center
* Edward S. Munyak, MS, PE, Former Fire Protection Engineer for the U.S. Departments of Energy, Defense, and Veterans Affairs. Contributing Subject Matter Expert to the U.S. Department of Energy Fire Protection Engineering Functional Area Qualification Standard for Nuclear Facilities
Dec. 4, 2007 - Eight Senior Republican Appointees Challenge Official Account of 9/11 - "Not Possible", "a Whitewash", "False" featured statements by
* Paul Craig Roberts, PhD, Assistant Secretary of the Treasury under President Ronald Reagan
* Catherine Austin Fitts, Assistant Secretary of Housing under President George H.W. Bush
* Morgan Reynolds, PhD, Chief Economist of the U.S. Department of Labor under current President George W. Bush
* Col. Ronald D. Ray, U.S. Marine Corps (ret), Deputy Assistant Secretary of Defense under President Ronald Reagan
* Mary Schiavo, JD, Inspector General of the U.S. Department of Transportation under Presidents George H.W. Bush and William Clinton
* Barbara Honegger, Special Assistant to the Chief Domestic Policy Adviser to President Ronald Reagan and White House Policy Analyst
* Edward Peck, Deputy Director of the White House Task Force on Terrorism under President Ronald Reagan. Former Deputy Coordinator, Covert Intelligence Programs at the U.S. State Department. Former U.S. Ambassador and Chief of Mission in Iraq
* Morton Goulder, Deputy Assistant Secretary of Defense for Intelligence and Warning under Presidents Richard Nixon, Gerald Ford and Jimmy Carter
Sept. 23, 2007 - Seven CIA Veterans Challenge 9/11 Commission Report - Official Account of 9/11 a "Joke" and a "Cover-up" featured statements by CIA veterans Raymond McGovern, William Christison, Melvin Goodman, Robert Baer, Robert David Steele, Lynne Larkin, and David MacMichael.
Sept. 5, 2007 - U.S. Navy 'Top Gun' Pilot Questions 9/11, featured the statement of Commander Ralph Kolstad, U.S. Navy 'Top Gun' pilot.
Sept. 4, 2007 - Former Congressional Office of Technology Assessment Senior Staff Member Calls for New Investigation of 9/11 featured the statement of Joel S. Hirschhorn, Ph.D., who served for 12 years as a Senior Staff Member of the Congressional Office of Technology Assessment and later as Director of Environment, Energy and Natural Resources for the National Governors Association.
Aug. 27, 2007 - National Academy of Sciences Member Calls for New 9/11 Investigation featured the statement of Lynn Margulis, Ph.D., world renowned scientist.
Aug. 21, 2007 - Former Chief of NIST's Fire Science Division Calls for Independent Review of World Trade Center Investigation featured the statement of James Quintiere, Ph.D., one of the world's leading fire science researchers.
July 16, 2007 - Former California Seismic Safety Commissioner Endorses 9/11 Truth Movement featured the statement of J. Marx Ayres, former member of the National Institute of Sciences Building Safety Council and former member of the California Seismic Safety Commission.
So, where is the burden of proof?
Shall I explain?