As per an IDC report, in US Mobile Content and Application Downloads still accounts to only 13% of Content revenue for Q42006. About a half (48.8%) of  this revenue is still coming from Messaging. 

There were 236 mln US wireless subscribers by the end of 2006. Wireless data revenue totaled $4.8 bln for Q4 2006, which equates to roughly 13.5% of average revenue per user (ARPU) or $6.74 per subscriber/customer per month. Of the total data revenue, 48.8% came from messaging in comparison to 13.0% from content and simple application downloads and 38.2% from other business- and consumer-oriented services and content, IDC says.

Source: » 236 mln wireless subscribers in the US in 2006 | IT Facts | ZDNet.com

 As per a report by CDC, 

More than a quarter of young adults have only cellphones, making them the leading edge of a strengthening move away from traditional landline telephones, a federal survey showed Monday.

One in four people aged 18 to 24 had only cellphones, as did 29% of those aged 25 to 29, the study showed. The percentages declined with age after that, with 2% of those 65 or over having only cellphones.

The trend away from landline phones affects the telephone industry, 911 emergency service providers, and government and private polling organizations, which rely heavily on random calls to households with wired telephones.

Source: Cellphone-only use growing among youths - USATODAY.com

Number of Camera Phone owners in US climbed to 106 Million in United States as per a press release by M:Metrics accounting to around 51% of total cell phone owners. So one in two have a phone equipped with camera.

In terms of % of subscribers, US is still behind Europe where as high as 75% of cell phone owners have a phone equipped with a Camera.

Source: M:Metrics, Inc., Copyright © 2007. Survey of mobile subscribers. Data based on three-month moving average for period ending 28 February 2007, n= 102,267 mobile subscribers in France, Germany, Italy, Spain, the UK and US.