From my review of Stephen Fry's 2004 comedy "Bright Young Things," a fine adaption of Evelyn Waugh's bleak comic novel Vile Bodies:
Nonetheless, the brilliance of Waugh's ear for spoken idioms has made Vile Bodies a steady seller for three quarters of a century. Those conversations help make watching "Bright Young Things" far more satisfying than reading Vile Bodies. Although Fry's ensemble comedy ... is rather slight, no film rendition of a major novelist's work has been this much more fun than the original book since Bogie and Bacall steamed up Hemingway's embarrassing To Have and Have Not.
For example, Peter O'Toole delivers a howlingly funny cameo performance as a passive-aggressive eccentric, one as striking as John Gielgud's similar role as Jeremy Iron's slyly mad father in the famous miniseries of Waugh's Brideshead Revisited. I went home sure that Fry had penned some new jokes because the character is so much funnier than I recalled. Upon checking the novel, however, I found that Mr. O'Toole, being a much better reader of dialogue than I am, had only drawn out hilarity that I'd never noticed.
A surprisingly high proportion of the great actors are great readers.