One in five U.S. households could be without a landline phone by the end of 2008, according to a white paper released Wednesday by Nielsen Mobile.
Seventeen percent of U.S. households — 20 million homes — have already ditched their home landlines, relying instead on mobile phones, Nielsen reported.
These “wireless substitutors” tend to live in smaller households with just one or two residents and have lower income-levels — 59% have household incomes of $40,000 or less.  A significant number moved (31%) or changed jobs (22%) just before discontinuing their landline service.