Their faces, smiling or solemn, have become all too familiar in newspapers and on television. The roster, a somber roll call -- Smith, Falaniko, Ramos, Lee -- seems to grow daily. Now, 1,000 American military personnel have died in the Iraq war. They are teens who went from senior proms to boot camp and battle and middle-aged men who put aside retirement and grandchildren for a war zone. What does the number mean?