Clint Eastwood does bicep curls backstage at Universal Studios. Jack Lemmon and Jimmy Cagney hang out at a luau with their wives. Frank Sinatra pitches during a game of baseball on the streets of Hoboken, New Jersey. In the pages of the new book Hollywood at Play: The Lives of the Stars Between Takes ($24.95, Lyons Press), authors Stephen X. Sylvester, Mary Mallory and Donovan Brandt have compiled photos of some of classic Hollywood's biggest names doing what we're not used to seeing them do: enjoy some downtime. It's a fascinating glimpse at Hollywood history and royalty in the pre–US Weekly era.