"The Future is Now" is the slogan for Hudsucker Industries.
Another Coen brothers reference is Major Hamar, a grizzled war veteran who wears an eye-patch and travels with a young girl. Much like Rooster Cogburn in True Grit (2010).
The "Barton Arms" boarding house that Rabbi and Satchel stay at shares its name with the Hotel in Miller's Crossing (1990) (which was itself a tease for the title character of then yet to be released Barton Fink (1991)).
Satchel following a white dog named Rabbit down the staircase where he meets a somewhat mysterious smoking man is a reference to Alice in Wonderland.
Clyde Tombaugh, the discoverer of Pluto, was born in Streator, Illinois, in 1906. His family moved to Burdett, Kansas, when he was 16. Burdett is about 300 miles west of Kansas City, Kansas. A marker similar to the one in this episode still stands there.