Arbitron Inc., a media audience measurement firm based in Columbia, Md., that the percentage of Americans who possess smartphones more than doubled in the past year, from 14 percent to 31 percent.

Here are more factoids from the study:

-- Facebook is now being used by a majority of all Americans age 12 and
over (51%); this number was only 8% when Arbitron/Edison Research first
measured the social media phenomenon in 2008.

-- A majority of American households now have two or more computers (51%);
as compared to 24% of households in 2002.

-- Usage of online radio is up significantly, with weekly usage of all
forms of online radio having doubled in the last five years;
self-reported weekly time spent with online radio is now nearly 10 hours
(9 hours 47 minutes).

-- Daily time spent with TV, Radio and the Internet combined has increased
by 20 percent in the last ten years, with self-reported daily usage now
at 8 hours 11 minutes compared to 6 hours 50 minutes in 2001.

-- Just under one-third of all Americans (31%) have plugged an MP3 player
such as an Apple iPod into their car stereo systems.

-- One in ten Americans report listening to Pandora Internet Radio in the
week before they were surveyed.

-- Among the 81% of American households with Internet access, two-thirds
now have a Wi-Fi network installed.

-- More than one-tenth of all cell phone owners have listened to online
radio streamed in their cars by connecting their phones to their car
stereo system.

More than 2,000 people were interviewed for the study.