@Ceili,
Where I live now, at work, when I ask someone's phone number, I'd say a good 95% of the time, no exaggeration, they give the area code when they give me their number.
A few weeks ago, our receptionist was out sick for an extended period, and we took turns covering for her. Over 3 weeks I probably answered almost all the calls coming in for at least 6 or 7 days. At least, I'd say 300 calls. Almost every single person calling in gave their area code with their number, and probably 90% of them gave 512 as their code. We have to record the phone number of every single person and business that calls. That's the old code that's been around for years.
What can I say? People are already giving their codes around here the vast majority of the time. Next month we get the new code....I'd say in a year everyone will pretty much be giving whatever code they have as part of their number....they're already doing it.
Edit - almost all the non-business calls that come in, meaning from families of patients, their caregivers, or the patients themselves, come from their cell phones, regardless of their age. Hardly anyone calls from a land line anymore around here.
In fact, at work all the field people i.e. nurses, aides, social workers, chaplans, etc, when they come in just use their cells to make all their calls while they're in the office handing in paperwork, etc. Ditto with the sales people who come in and out, and the individual managers who because of their position are in and out. They never use the office phones, just their cells.