The conical First Earth Battalion solar stove used by George Clooney's character bears an uncanny resemblance (though miniature) to the Sibley stove which was also conical but used wood coals as its heat source. It was invented for the U.S. Army in the 1850s by Major (later Confederate General) Henry Hopkins Sibley, and the Army discontinued its use by World War II.
Jeff Bridges' character Bill Django is, in fact, based on Army Lt. Colonel Jim Channon, who wrote the First Earth Battalion field manual (which is shown in the film). Just like Django, Channon took a leave of absence (with pay) from the Army to go on a fact-finding tour of the New Age Movement in the mid-1970s before coming back and writing the First Earth Battalion manual. The movie, based on the book by Jon Ronson, combines two or three separate programs - the Army's Remote Viewing program (run by the Army's Intelligence and Security Command), the "Jedi" program run by the Special Forces, and Jim Channon's First Earth Battalion (which was a concept and a field manual rather than an operational unit).
The one-sheet (advertising poster) for this movie is a spoof of a frequently used style for movie posters in which, instead of trying to communicate anything about the plot or content of the film, the poster just contains multiple stacked faces of the stars. On this poster, the last face visible in the row is a goat's, and the billing line above their photos reads, "George Clooney, Jeff Bridges, Ewan McGregor, Kevin Spacey, and Goat." Also, it's an obvious reference to the iconic drawing posters form Soviet communist era, showing profiles of Karl Marx, Friedrich Engels and Vladimir Lenin (in some historic eras or world regions, often completed by profiles of Joseph Stalin or Mao Zedong).
George Clooney's character Lyn Cassady appears to be based partly on US Military top Remote Viewer Joe McMoneagle, and RV Project Database Manager Lyn Buchanan. Reference to McMoneagle is supported in both his being a favored resource, and in a scene where information on a missing general is provided by Cassady in a Remote Viewing session - likely drawn from inspiration from McMoneagle's partly successful attempt to RV kidnapped US Brigadier General Dozier's location in Padua Italy (1981). Also as a reference to Lyn Buchanan, the scene where computer systems are fried and destroyed, seemingly by Lyn, resulting in his initial recruitment by General Hopgood, is also very close to fact.
Jeff Bridges' character Bill Django seems to be based around US Military Remote Viewing project originator Captain "Skip" Atwater. References to Django's fixation with altered states of consciousness throughout the film seem to poke fun at Capt. Atwater's interests in the Monroe Institute and what some might call the "pseudo yogic" early cognition workshops done there.
When George Clooney's character mentions the poem about the sailor and the seagull (should be an albatross), he is talking about the poem 'The Rime of the Ancient Mariner' by English poet Samuel Taylor Coleridge.