Keira Knightley is one of those beautiful celebrities who is never smiling. But she's not trying to mimic Victoria Beckham—she just has a nervous disposition. Keira insists she doesn't pose that way deliberately. She says, "I think I was pouty when I was 16 or 17 when my first films came out and it's sort of stuck. I don't know, maybe I still do it. It's when I'm nervous and my neck gets really really tense and then that pressure sort of squeezes up to my lips and they push out and well, there you go, that's the pout."This might be mean, but Keira almost looks better when she doesn't smile. She has that mysterious look to her that makes her sexy. So keep those pearly whites right where they are!