It's the 50th anniversary of the original "Ocean's 11" movie, starring the Rat Pack (Frank Sinatra, Dean Martin, Sammy Davis Jr., Joey Bishop and Peter Lawford). Life.com discovered some new, mostly unstaged photos of the Rat Pack and published a gallery. Following are a few of the photos and small versions of the 25 picture gallery. Clicking on "enlarge" takes you to the Life.com site for the full visual experience.
Pictured, from left: Peter Lawford, Pack leader Frank Sinatra, Sammy Davis, and Dean Martin outside Las Vegas' Sands Hotel and Casino, circa 1960.
"I don't discuss his girl with Frank or who he's going to marry. All I discuss are movies, TV, golf and drinking." -Dean Martin, date unknown. Pictured: The stars, photographed in a recording studio by LIFE's Allan Grant, take a cigarette break during the recording of Sleep Warm in 1958. The album was re-released in 1963 with a much more direct title: Dean Martin Sings/Sinatra Conducts.
"By the time we got to Miami, I was familiar enough with Frank that I was able to photograph him inside the hotel steam room. I couldn't go inside because my lenses would have fogged up. But the steam room had a glass window, and Frank sat right next to it. I didn't ask him to, so maybe he did that for me." --LIFE photographer John Dominis describing a moment from his months with Sinatra, from his introduction to the book Sinatra: An Intimate Portrait of a Very Good Year
"Be especially good tonight. My leader is out front." --Sammy Davis Jr. to the cast of Golden Boy on the night Frank Sinatra was in the audience, 1964. Pictured: Sammy eats spaghetti in his dressing room while watching The Huntley-Brinkley Report ("My only contact with reality," he tells LIFE. "Whatever I'm doing, I stop to watch these guys"). Reflected in the mirror: LIFE photographer Leonard McCombe.