Editor Roy Thomas, Writer Mike Friedrich, and artist Dave Cockrum went out to lunch at the Autopub, a car-themed restaurant in the bowels of the General Motors building, to brainstorm. Sitting at a table made from car chassis, surrounded by monuments to assembly line production, the trio discussed the idea of replacing the old X-Men members with a multi-ethnic team of mutant heroes. Cockrum, who filled his notebooks with sketches of original costume designs, ideas for hire at the ready, was a one-man character machine. He went home and perused his files, selecting characters he’d kicked around over the years, while in college, while in the army, and while working on DC’s Superboy and the Legion of Superheroes: Typhoon. Black Cat. Mr. Steel. Thunderbird. Nightcrawler. The project went into limbo for months, however, and by the time the title was on the schedule in late 1974, Len Wein had replaced Friedrich; Typhoon and Black Cat were combined into “Storm”; Mr. Steel was “Colossus”; and Nightcrawler had evolved from an actual demon into a mutant German acrobat with a pointed tail.

(Illustration by Dave Cockrum, 1975; Text excerpted from Marvel Comics: The Untold Story, 2012)

And here’s what became of the Autopub:
http://www.nytimes.com/2008/10/23/nyregion/23thennow.html
That’s right: The X-Men were conceived of in the Apple Store.