One of the most popular actresses in show business, Natalie Portman opened up about her tendencies to take challenging job opportunities. Having premiered her movie "Black Swan" last night, the 29-year-old dished, “Work-wise, I try to do things that scare me, because I know they’re going to challenge me." Miss Portman continues, “But I didn’t know what I was in for with Black Swan. I didn’t realize what it was going to be like. But the cliché is true, the more you put in, the more you get out." With the film due out in theaters on December 3, Natalie finished by telling, “Everyth...