Paris Hilton wore a very low-cut number as she boarded a plane to Australia from LAX. The 31-year-old's blue halterneck dress with yellow designs was also backless, showing off her toned body. She paired her look with a flopy brown hat and massive dark sunglasses as she headed into the terminal. She looked cute and stylish. The star was heading to Sydney to open The Marquee club and she tweeted her excitement.