With so many flat-chested ambassadors succumbing to implants (Nicole Ritchie, Kate Hudson, we’re talking to you), the A-and B-cups among us look to Knightley and Portman for inspiration. Knightley, 26, spoke out in 2004 against publicity shots for her film King Arthur, which had been photoshopped to make her appear more top-heavy. She’s unapologetic about her barely-theres, seeming to revel in their teeny size. As for new mom Portman, 31, her Black Swan pirouettes would have surely toppled had her leotards been filled out with double Ds. Their petite bosoms remind us how freeing -- and sexy -- it is to wear bra-less sundresses.