How to put a "1" in front of contact phone number for calling long distance

I don't have a "1" for calling long distance in front of every phone number in my contact directory. If I am in a position where I need to make a non-local call to such a contact, I need to put a "1" before their phone number. Is there an easy way to do this, or do I need to edit the stored phone number? Some "smart phones" have a single button to press that adds the "1" at the time of dialing.