To celebrate the 20th season of "Big Brother," CBS has announced that celebrities will be joining the game. The new show, simply titled "Celebrity Big Brother," will be be hosted by long-time "Big Brother" host Julie Chen. The reality TV competition brings a group of strangers together to live in a house under 24-hour surveillance where they compete in games and vote one another off the show. The network has not yet announced the show's premiere date or which celebrities will be involved. The U.