ON THE PHONE: A new report from the Pew Internet & American Life Project finds that 78 percent of young people, ages 12 to 17, now have cellphones. Nearly half of those are smartphones, a share that's increasing steadily.

MOBILE SURFERS: One in four young people are "cell-mostly" Internet users, a percentage that increases to about half when the phone is a smartphone. Girls ages 14 to 17 were among the most likely to say their phones were the primary way they access the Web.

MARKET IMPACT: As this generation comes of age, the way corporations do business and marketers advertise is likely to change to adapt to a more mobile Internet.