iPhones sweep list of 2011's best-selling smartphones in U.S.

In its annual "Mobile Future in Focus" report released on Thursday, telecom analytics firm comScore reports that Apple's hot-selling handsets also took the top two spots in the EU5 (France, Germany, Italy, Spain and the U.K.), while the recently debuted iPhone 4S took the fifth spot in the region despite only being available for less than three months.

The firm's MobiLens survey showed that the iPhone 4 was the most acquired smartphone in the U.S. and the EU5, with the two-year-old iPhone 3GS taking second place in both regions most likely due to the device's low price-of-entry.

Echoing earlier reports, Apple became the largest smartphone vendor in its home country, attaining over a quarter share of the market with 29.6 percent. The Cupertino, Calif., company also led the smartphone markets of the U.K. and Japan with 26.4 percent and 33.6 percent, respectively.

The iPhone maker's high sales can be attributed to an overall shift toward smartphones, as the devices overtook feature phones for the first time in many countries during 2011. Sales in America, for example, surpassed those of so-called "dumb phones" in July, 2011.

Total smartphone audience grew dramatically in the U.S. and EU5 over the second half of last year, with key factors like 3G and 4G availability and carrier subsidy pricing playing large roles in the shift. During the second half of 2011, the number of smartphone users in the U.S. grew 14.8 percent to account for 41.8 percent of total mobile users, while the EU5 saw a similar 13 percent bump to end the year with 44 percent.

With the share of smartphones on the rise, Google's Android platform proved to be the most successful OS, taking nearly half of the U.S. market and snagging the top spot away from the dying Symbian platform in the EU5.

Data suggests that the ballooning population of Android users are coming from RIM's sinking BlackBerry ship, though Apple's iOS also benefitted from the BlackBerry exodus as the Canadian phone maker's share of the market halved in the U.S. over 2011 to end at 16 percent.

As smartphones become more affordable, the rate of adoption is quickly making the industry a part of the mainstream consumer segment.

The drive down in hardware and carrier costs has allowed those demographics that have not traditionally been associated with the smartphone market to pick up a new device. Fastest growing segments were members of six-person households and those making less than $25,000 a year, and showed a 99 percent and 98 percent uptick, respectively.

comScore notes that 2012 will be a significant year for the U.S. smartphone market as device adoption passes 100 million. The firm sees iOS and Android holding court over their competitors as the two companies' app ecosystems are far more robust than competing platforms.

As a closing note, the study mentions how many times the throne to the top smartphone OS has changed hands in the U.S. over the past six years; from Palm, to RIM and Symbian, to Microsoft, to Android. Apple has never laid claim to the title.