Image credit: John Minchillo/AP Photo

Times of national disaster not only can bring together people, but also rival technology companies.

This afternoon, AT&T and T-Mobile have announced that they will be working together in the wake of Hurricane Sandy to provide more service and coverage in areas hit by the storm. The two cellular providers will share networks and roaming capabilities in New York and New Jersey, an AT&T spokesman told ABC News.

AT&T and T-Mobile customers will be able to place calls as they usually do. The calls just might be carried over a network they don't subscribe to. For instance, T-Mobile customers in New York City who have had very little service during the storm aftermath will now be able to place calls over AT&T's network.

In each case, calls will be carried over the most operational network in the area.

"This agreement is possible because AT&T and T-Mobile use the same underlying wireless network technology," AT&T spokesman Mark Siegel told ABC News. "Which network a customer is on will be completely transparent. The customer won't even notice."

There will be no extra costs to users, and no roaming fees or extra line items on bills.

Both AT&T and T-Mobile use the same GSM and UMTS network technology.

Verizon and Sprint use different technology, so they aren't involved in this arrangement.