Of note, receive a free modem or wireless gateway when you subscribe to the FastAccess DSL Ultra or Xtreme plans. You'll be charged for the device on your first bill, but rebate instructions will be mailed within four to six weeks. You must redeem the credit online within 30 days of receiving your instructions. (The rebate may come in the form of a bill credit or an AT&T Reward Card.) Deal ends December 31.