Shaquille O'Neal - who spent much of the week teasing fans about his plans to dress in drag and ride the T on Halloween - tweeted yesterday that he had left a pair of sneakers autographed by himself and Kevin Garnett somewhere along Route 2 in his temporary hometown, Sudbury. Where exactly were they? "Ask da cows," Shaq tweeted. As of 9:30 p.m., Shaq hadn't been spotted on the subway, but he was challenging fans to find him downtown, offering tickets to the next home game, after posting pictures of himself dressed as his female alter-ego, whom he called "Shaqeeta." He later posted a video of himself lipsyncing to Beyonce's "Beautiful Nightmare" as he drove through Boston.