Reply #7: Cubans have referred to the U.S. as "Yuma," as some travellers have noticed, [View All]

and it has been explained to them to have been derived from Cubans' seeing the movie "3:10 to Yuma," which was released in the 1950's. Apparently they're going to be ready to see the remake of the movie soon:

Cubans to see new La Yuma
Town name is lingo for United States, dating to 1957
By WILL WEISSERT | The Associated Press
September 4, 2007

HAVANA It's not big or famous and it's certainly not close, but Yuma, an Arizona desert town near the borders with California and Mexico, is Cuba's most talked-about American locale.

"La Yuma" is Cuban street lingo for the United States, and "Yumas" can be Americans or foreigners from any non-Spanish speaking country.

Many trace the term to 3:10 to Yuma, the cowboy classic based on an Elmore Leonard short story that arrived here after it hit U.S. theaters in 1957. The slang should get a boost with the release of a remake of 3:10 to Yuma, starring Russell Crowe and Christian Bale, opening in America on Friday.

"A new movie could mean Yuma is used more by young people who know nothing of the original," said Fernando Carr, who writes a column on language for the official magazine Bohemia.

Washington's embargo prohibits most U.S.-Cuba trade. But American films are commonly shown on state TV and in crumbling 1950s theaters where tickets cost less than a U.S. nickel. A thriving black market for pirated DVDs and videos also likely will ensure some Cubans see the 2007 version of 3:10 to Yuma.

More:
http://www.sun-sentinel.com/news/local/cuba/sfl-flhcubayuma0904nbsep04,0,6935583.story