A survey by the National Center for Health Statistics finds that the majority of Americans live in a home without a working landline. That doesn't mean the majority of homes no longer have a landline. Those most likely to be cell-only are renters, young people, and people living with unrelated roommates. You can figure those are greatly-overlapping groups. Read more about the survey at Geeks Are Sexy.
One impact is the disapearance of our yellow pages books, and thus company.