'Megachurches' draw big U.S. crowds By Joyce Kelly and Michael Conlon CHICAGO (Reuters) - On a recent Sunday at Willow Creek Community Church, a Christian rock band joined by dancing children powered up in the cavernous main hall, their images ablaze on several gigantic screens. Thousands of worshipers from the main floor to the balcony and mezzanine levels were on their feet rocking to a powerful sound system. Outside cars filled a parking lot fit for a shopping mall. Inside some people drifted into small Bible study groups or a bookstore and Internet cafe for lattes, cappuccinos and seats by...