Paris Hilton turned her Hollywood home into Club Paris on Monday night (17APR06) when she staged a surprise birthday party for her boyfriend STAVROS NIARCHOS. The socialite-turned-actress scrapped plans to party in Las Vegas, Nevada and assembled select friends at her home to celebrate her Greek hunk's 21st birthday. The party people included Nicky Hilton, movie-maker Brett Ratner and Milla Jovovich, while Courtney Love and pal Billy Corgan made a surprise midnight appearance. Hilton topped off the celebration by reportedly diving into her pool fully clothed.