I say bring in an Ex-BB player from the past (not in the top 20, of course) and have them be the immediate HOH. They'd have to be in sequester since before the game started though, but saw the tapes or something. It would really surprize the HGs if Julie says, "Alright Houseguests, there will not be an HOH competetion tonight. Instead..." The look on their faces would be priceless.