Barack Obama's campaign is considering moving his nomination acceptance speech at the Democratic National Convention from the Pepsi Center convention hall to Invesco Field at Mile High to accommodate the uncredentialed masses, sources say. The move would mark a major departure from tradition, but would be in keeping with the candidate's desire to build a large grass-roots campaign focused on "change." It also would leave behind the multi-million-dollar broadcast studios, media offices and high-tech podium and stage to be constructed at the Pepsi Center.