A construction crew this week laid the cornerstone for a 1,500-foot skyscraper where the World Trade Center once stood. The Freedom Tower, which will be taller than the Trade Centers fallen twin towers, wont be completed until 2008. Architects are still squabbling over the design, and developer Larry Silverstein is fighting insurers in court for money he will need to rebuild at the site. Despite the uncertainty, political leaders said the unveiling of the 20-ton granite cornerstone marked a symbolic victory. What our enemies sought to destroyour democracy, our freedom, our way of lifestands taller than ever, New York Gov. George Pataki said.