Meghan McCain, one of the daughters of former Republican presidential candidate John McCain, has apologised for using Twitter to post a picture in which she displayed an ample amount of cleavage. McCain, 24, who helped her father campaign for president last year and is a columnist for the website The Daily Beast, posted the photo she took of herself on Twitpic late on Wednesday. "My 'spontaneous' night in is my Andy Warhol biography and takeout," she said in a "tweet" accompanying the picture. "I'm getting old." After a string of comments were posted about the picture - mostly from apparently...