After a shaky start this year, the US box office has exploded with a series of summer blockbusters - not least Warner Bros. Hangover: Part II which has grossed about $118m in four days. It is the first time an R-rating comedy has topped the Memorial Day box office. The weekend's other big release - Kung Fu Panda 2 - also did well. The family-friendly sequel will clock up about $70m by Monday.
Peter Bowes reporting from California