A question I used to often hear when I was a kid was, 'Do you have the phone on?'
The person asking the question did not mean have you switched your phone on. They meant do you have a telephone at home. A positive response would lead to an exchange of numbers or whatever.
Ten year ago it was almost unimaginable that someone would not have a home telephone. It is quite imaginable now. There is a drop of profit forecast for our favourite big telco as people no longer feel the need to be gouged for the home telephone. This seems a bit odd to me as unless you have cable internet, without a fixed line, you can't have dial up internet or adsl. This surely is the only thing that people will keep the home phone line for. Although, much as I dislike talking on the telephone, the fixed line is far more preferable than a mobile.
It was less than ten years ago that our phone bill for three months was around $40. I expect we use the phone less now, but it is well over $30 per month. It costs us $6 a month just for caller ID. This is a ridiculous charge.
As we have cable internet, I think at some time in the future, we will do away with the fixed line, although because of bundling of internet, mobiles and home phone, the economics of it would need to be carefully studied.