Pop superstar Britney Spears amazed onlookers at a Las Vegas club on Friday (31Aug07) night - when she swapped dresses with a friend. The Toxic singer arrived to host the opening party of new venue LAX wearing a short cream-coloured dress. After performing her duties as a host, she was later spotted wearing her friend's long red dress at the club's VIP lounge, Noir Bar, while her pal was wearing the outfit Spears had arrived in.