Prince Harry left the Andaz hotel in San Diego yesterday toting a water bottle and wearing a hat with an American flag embroidered on it. It was just a few days ago that Prince Harry landed in California to start his Apache helicopter training at the nearby El Centro naval base, but he took advantage of some time off this weekend to grab a burger and brew with his fellow pilots. He was also seen partying until the early hours yesterday morning with a brunette at the Andaz's nightclub, the Ivy. Harry will spend about four weeks in California before leaving to continue his training in Arizona. Harry's trip is work-centric, but in keeping with a pilot-training tradition, he'll likely fit in an excursion to Las Vegas during his time in the states. While Harry focuses on the Royal Air Force, Prince William and Kate Middleton have been dedicating themselves to philanthropy back home in Enland. The couple recently launched the new Oak Center for Children and Young People, a cancer-treatment center, in London.