Parties! The style, stars and scoop from Hollywood's hottest events

Unlikely duo Sienna Miller and Dennis Hopper teamed up to introduce a performance by Lily Allen. Kiefer Sutherland, American Idol judges Randy Jackson and Simon Cowell, and Ryan Seacrest also put their presenting skills to good use when they introduced a star-studded roster of stage acts from Elton John—one of Diana's all-time favorites—to Pharrell Williams.