Interesting question! This is the photo anon is referring to. Does anyone know?

edit - closer look:

Neil Young and Dennis Hopper

Ursula Andress and James Dean

Fred Astaire and Bing Crosby

Bing Crosby, Frank Sinatra and Judy Garland

Vincent Price and Alice Cooper

Will Arnett and Jason Bateman

Neil Gaiman and Terry Gilliam

(Source: whosay.com)

Paul McCartney and Mick Jagger, 1967

Constantin Brâncuși, Marcel Duchamp and Mary Reynolds, Villefranche, 1929

Peter Sellers and Stanley Kubrick

Elizabeth Taylor and James Dean, 1955

This happened. Thanks Tumblr. Do I win?

Rita Hayworth, Orson Welles and Marlene Dietrich

Ernest Hemingway and Frank Capra