By Leah Abrahams
Updated Oct 06, 2011 @ 5:55 pm
Richard Young/Startraksphoto

Hollywood royalty Gwyneth Paltrow and Cameron Diaz rubbed shoulders with Prince Philip, Duke of Edinburgh at the re-opening of Mayfair's members-only hot spot The Arts Club in London. After posing for photos, Paltrow hit the stage to belt out a few songs with Mark Ronson and The Knights Before. Click through to see more stars at last night's hottest events!