AT&T (T) is down 66 cents to $28.28, now the biggest loser in the Dow Jones Industrial Average, and falling to session lows on news Verizon (VZ) will begin offering Apple iPhones beginning early 2011. AT&T shares saw a slide on increasing volume on the news and options activity is now running 2.5X the average daily, with 39K calls and 56K puts traded so far. Oct 29 puts are the most actives. Verizon, meanwhile, is up 36 cents to $33.44 and options volume is 3.5X the average daily, with 59K calls and 32K puts traded. Nov 33 and Oct 34 calls are the most actives.