Phone

Smartphone adoption marches on, with 44% of mobile phone users owning a smartphone, compared with 18% in 2009, according to Nielsen.

Its monthly survey of 25,000 mobile consumers finds that the majority of those ages 25 to 34 (64%) and 18 to 24 (53%) now own smartphones.

Messages sent via smartphones are replacing cellphone calls. 81% of mobile phone users have sent or received messages in the last 30 days, up from 75% in 2009.

Messages sent and received rose 35% across gender and all ages, while voice minutes were down 12%. Women are heavier mobile phone users than men for voice calls and messages.

Women sent 802 messages in the last 30 days, up from 593 in 2009; men sent 604 messages, up from 420.

Meanwhile, women's talked for 771 minutes in the last 30 days, down from 861 in 2009; men used 605 voice minutes, down from 679.

More findings from Nielsen's Mobile Media Report:

-- Apple remains the top smartphone maker in the U.S., with nearly 29% of the market, while Android is the most popular operating system, owning 44% of the U.S. smartphone market.

-- Smartphone app downloaders have an average of 33 apps on their devices, up 22% since 2010. iPhone app users average 44 apps; Android OS smartphones report 32.

-- Those 24 and under send and receive the greatest volume of messages; in fact teens (13 to 17) send about three times the messages each month (3,417) than do the 35-to-55 age group (1,143).

-- But older people consistently are texting more, with the number of messages sent and received by those 55-and-up doubling to 231 monthly, up from 99 in 2009.

-- Teens' monthly messaging dropped to 3,417 vs. 3,729 in 2010.

-- 87% of those who have downloaded an app in the past month have used a deal-of-the-day website. The most popular daily deal sites are Groupon (79% used it), Living Social Deals (48%) and Yelp Daily Deal (9%).