• by Mark Walsh  @markfwal, November 3, 2011

Smartphone penetration in the U.S.  is creeping towards the halfway mark as 2011 comes to a close. According to new data from Nielsen, 43% of all U.S. mobile users. A majority of people 44 and under now own a smartphone, and nearly two-thirds (62%) of those aged 25-34 have one.

After younger adults, the fastest growing group of smartphone users are those 55-64. Smartphone penetration among this older group is only 30%, but it jumped 5 percent this quarter, according to Nielsen. Around 40% of 12-17 year-old teens and 40% of 45-54 year-olds reported owning a smartphone, as opposed to a more basic feature phone.

As the smartphone market expands, Android remains the most popular smartphone operating system in the U.S., with 43 share. Apple is the top smartphone maker, with 28% share.