Most times when Paris Hilton is at a party, she’s been called there as a celeb guest. This time around, at the Hard Rock Hotel & Casino’s Vanity nightclub the evening affair was one that was special to her. Here’s more for fans, the official launch of ParisHilton com was celebrated with much fanfare. Sin city isn’t complaining, and the party sure looks hot. With her slim frame, anything looks good on her, so the tight-fitting black dress was a hit. Obviously, the shutterbugs have had a ball because there’s more pictures than you can imagine, and of course fans got regular updates with Paris tweeting about the event as it happened.