A vast amount of credible evidence in the public domain backs up the claim that Extraterrestrial beings have visited Earth. Below are just some of the many web sites that collectively offer a wide range of this evidence.

The EXTRA Campaign makes no claims regarding the accuracy of information on these web sites. However, it is precisely this kind of information that inspired the idea to develop a ballot initiative to create an Extraterrestrial Affairs Commission in Denver, Colorado as a model for the world.

http://www.disclosureproject.org/ - Hundreds of very credible witnesses recently admitting their involvement and experiences with UFOs and even Extraterrestrial intelligent beings visiting Earth.

http://www.stanromanek.com - Stan Romanek, a Colorado resident,  has had encounters with craft and extraterrestrail beings since the year 2000.  He's been an unwitting participant thrust into this bizarre and twisted series of events involving government agents, extraterrestrial beings, unexplainable craft, balls of light, threats, floating objects, bizarre communications, advanced scientific equations, implants and much more. If it weren’t for video and audio recordings, photos, physical evidence, police reports and hundreds of witnesses confirming these accounts, he and others would question his sanity.

http://www.thephoenixlights.net/ - New 11th Annniversary Edition of award-winning The Phoenix Lights Documentary - WE ARE NOT ALONE Released March 2008

http://www.paradigmresearchgroup.org/main.html - View PRG’s coverage of Jeff Peckman’s EXTRA Campaign

http://www.cohenufo.org/Military%20Nuclear%20Specialists%20Testify%20To%20UFO%20Reality.htm - Quotes by military officers about extraterrestrial UFO's disrupting nuclear missile systems and disabling a nuclear tipped missile while in flight.

http://www.nicap.org/babylon/missiles_incidents.htm - UFO sightings at ICBM sites and nuclear Weapons Storage Areas, By Robert L. Hastings

http://www.stargate-chronicles.com/those_who_know.html  - web site of a former NASA engineer with inside knowledge of UFO's observed during NASA activities.

http://www.presidentialufo.com/ - History of U.S. Presidents and their familiarity or involvement with UFO's and Extraterrestrials

http://www.nuforc.org/ UFO Reporting Center, by State or date

http://www.theblackvault.com/modules.php?name=core&showPage=true&pageID=25
Hundreds government documents acknowledging and addressing UFOs

http://www.majesticdocuments.com/documents/pre1948.php - Excellent collection of government documents referencing UFO's and Extraterrestrials. At this URL page, select "Franklin D. Roosevelt on Non-Terrestrial Science and Technology, 22 February 1944", a letter where he mentioned "...coming to grips with the reality that our planet is not the only one harboring intelligent life in the universe."

http://www.ufoevidence.org/ - In-depth, quality and scientific research on the UFO phenomenon
http://www.ufoevidence.org/topics/PublicOpinionPolls.htm - Public opinion polls on UFO's and Extraterrestrial beings.

http://www.ufodigest.com/balducci.html - "Vatican Official Declares Extraterrestrial Contact is Real" (article)

http://www.exopolitics.com - EXOPOLITICS: Politics, Government, and Law in the Uniververse

http://www.exopolitics.org/Exo-Comment-38.htm - Policital implications of the extra-terrestrial presence
Former Canadian Defense Minister Speaks Out on Extraterrestrial Visitors & Government Secrecy

http://www.thewakeupcallanybodylistening.com/Pages/thetrailer.html - Excellent documentary on crop circles with an amazing shot of how one is created, and it's clearly not with earthly technology. Even the trailer is impressive.

Books:
UFOs and the National Security State, by Richard Dolan

The Phoenix Lights, by Lynne D. Kitei, M.D.

The Day After Roswell, by Col. Philip Corso

UFO Politics at the White House:  Citizens Rally 'round Jimmy Carter's Promise, by Larry W. Bryant

Alien Rock: The Rock 'N' Roll Extraterrestrial Connection, by Michael C. Luckman