Get a $5 coupon at Radio Shack just for checking your eligibility for a wireless upgrade on your AT&T, Sprint or Verizon account

If you've got a wireless account with AT&T, Sprint or Verizon, Radio Shack will give you a $5 coupon off a $5 minimum purchase just for checking to see if you're eligible for an upgrade.  You can check the eligibility of your account in a Radio Shack store or online, here.