Apple's heavily hyped ipad went on sale last saturday in the united.Excited customers were crowding to get their hands on what some see as a"garhe changer"in the compater industry.The Apple flag ship store in New York greeted hundreds of people who had waited since just after dawn.Many of the shoppers were from outside the united states,which is initially the only country to sell the touch-screen tablet,retailing in between $499 and $829.