In the fall of 2001 when the dust and ash from the World Trade Center were still in the air, Jim Whitaker, a documentary filmmaker, decided to photograph everything happening at ground zero. By the spring of 2002 three cameras were pointed at the pit, each taking one shot every five minutes, round the clock. Months later, three more cameras were added. That was the beginning of Project Rebirth, a nonprofit organization dedicated to creating a historical record of the rebuilding. Today www.projectrebirth.org, a Web site produced with the Alfred P. Sloan Foundation and AOL , opens for public viewing....