You*72 to forward a phone. How do you unforward it?
If your cell phone provider offers the more standard 72 option to forward calls, then you can use 73 to "unforward" calls.
For most providers setting up call forwarding is as simple as dialing *72, pressing "send" and then waiting for the tone to sound. After that you simply enter the number to which you wish calls forwarded.
The two exceptions to this appear to be AT&T and Cingular; for each of these providers you need to call a customer service representative at the company to have your calls forwarded, as well as to cancel call forwarding.
NBC News reported that Sprint has announced that forwarding fees, as well as late fees and overage charges will be waived for customers impacted by Hurricane Sandy.