Please leave business and residential land-based locations alone. Reprinting business cards, stationery and advertising brochures and repainting delivery trucks is expensive. The inconvenience to residential customers who have to notify friends and family isn't insignificant either and it isn't worth the aggravation to phone company customers and employees. After a long day at the office, in the privacy of one's own home, no one likes to dial an area code for a local call. When we call for reservations at a restaurant or want to call Fred or Marge across the street to go out to dinner, we don't want our dialing hand to feel like they are located in Dallas or San Francisco.
Nobody cares what their area code is for their cellular phone or modem.
I answer my cellular when it rings and punch in the area code in all my outgoing calls anyway. The PC dials all my modem calls. Almost everybody cares about what their residential area code is. I was proud of area code 904. I had it monogrammed on all my dress shirts.