Paris Hilton at the Vienna Opera Ball

Paris Hilton turned fairytale princess for the night as she attended Vienna's glamorous Opera Ball on Thursday. Gone were her skin-tight mini-dresses and skinny jeans, replaced by a lemon-hued gown and a generous sprinkling of diamonds. The Simple Life star, who was accompanied by her mum Kathy, was guest of honour at the glittering occasion. Like Geri Halliwell and Pamela Anderson before her, she was attending at the personal invitation of construction magnate Richard Lugner. As an heiress to the Hilton hotel fortune, Paris is, of course, not unused to mixing in high society and the poised blonde was the epitome of elegance and bonhomie as she chatted to her 74-year-old host. Tickets to the prestigious ball sell out months in advance and are snapped up by 4,500 Austrian and foreign celebrities, dignitaries and socialites. Paris, 25, very nearly didn't make the evening, however, after running into problems en route in Munich, where she was told her passport had expired. Luckily the US ambassador to Austria stepped in and vouched for her, meaning she could enter the country after all.