WASHINGTON - Peace mom Cindy Sheehan vows to tie herself to the White House gates when the U.S. death toll in Iraq hits 2,000. "I'm going to give a speech at the White House, and after I do, I'm going to tie myself to the fence and refuse to leave until they agree to bring our troops home," she said in an interview published yesterday by Reuters. "I'll probably get arrested, and when I get out, I'll go back and do the same thing," she added....