Nicole Kidman's astonishing resemblance to Virginia Woolf in The Hours had even her co-stars seeing double. But it wasn't the famous literary figure that Miranda Richardson saw when she looked at Kidman. "She reminded me of a girlfriend of mine," laughs the two-time Oscar nominee. "I was like, 'Oh my God, it's Kate.'"

Richardson — who plays Virginia's sister Vanessa in the highly anticipated film (opening Dec. 27) — believes all the identity confusion worked to her advantage. "I suddenly saw somebody that I had a very particular affinity with," she says, "[which] was good for the sibling thing."

Of course, the sisterly bond between Virginia and Vanessa in The Hours can hardly be called traditional. For starters, in one of the movie's more ambiguous moments, the duo share a passionate smooch. Laughing, Richardson says Kidman was a "fabulous" kisser, adding that the shocking liplock "didn't go on long enough."

What's Richardson's take on the incestuous buss? "I think it's about how Vanessa can never quite give Virginia enough; she can never prove to her how she feels," explains the actress, whose performance in David Cronenberg's Spider could earn her a third Oscar nod. "There will always be a divide [between them], and that is something that isn't anybody's fault... Ultimately, it [has to do with] Virginia's aloneness."