Contacts - add a "+1"

Contacts - add a "+1"

I am travelling out of the country, and would like my address book accessible during travel. In order to make international calls back to the USA, I need to add a "+1" to the beginning of the phone number.

Is there a way to add a "+1" to the phone numbers?

Alternatively, is there a way to tell the phone to automatically add the "+1" to numbers from the contacts?