The conical First Earth Battalion solar stove looks like a smaller 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. The Army discontinued its use by World War II.
Jeff Bridges' character Bill Django is based on Army Lt. Colonel Jim Channon, who wrote the First Earth Battalion field manual. In the mid-1970s, Channon took a leave of absence (with pay) from the Army to go on a fact-finding tour of the New Age Movement, before coming back and writing the First Earth Battalion manual. The movie 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).
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. A scene where information on a missing general is provided by Cassady in a Remote Viewing session is likely drawn from inspiration from McMoneagle's partly successful attempt to RV kidnapped US Brigadier General Dozier's location in Padua, Italy (1981). The scene where computer systems are destroyed, seemingly by Lyn, resulting in his initial recruitment by General Hopgood, is very close to fact.
The advertising poster for this movie is a spoof of a frequently used style for movie posters. Instead of trying to communicate anything about the plot or content of the film, it 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." It's also a reference to the iconic drawing posters from the Soviet communist era, showing profiles of Karl Marx, Friedrich Engels and Vladimir Lenin (in some eras or world regions, often completed by profiles of Joseph Stalin or Mao Zedong).
When George Clooney's character mentions the poem about the sailor and the seagull, he is talking about the poem 'The Rime of the Ancient Mariner' by English poet Samuel Taylor Coleridge, which involves an albatross.
Timothy Leary was a psychiatrist who controversially started extolling the therapeutic benefits of LSD late in his career. A song by the Moody Blues, "Legend of a Mind," begins with the line "Timothy Leary's dead", referenced by a similar line in the film.