According to The NPD Group, Apple’s iPhone 3G surpassed the Motorola RAZR as the leading handset purchased by adult consumers in the U.S. in the third quarter (Q3) of 2008. RAZR had been ranked by NPD as the top-selling consumer handset for the past 12 quarters.

Even with stronger consumer sales of iPhone, and the mobile phone market’s normal seasonal uplift after Q2, domestic handset purchases by adult consumers declined 15 percent year over year in Q3 to 32 million units. Consumer handset sales revenue fell 10 percent to $2.9 billion, even as the average selling price (ASP) rose 6 percent to $88.

“The displacement of the RAZR by the iPhone 3G represents a watershed shift in handset design from fashion to fashionable functionality,” said Ross Rubin, director of industry analysis for NPD. “Four of the five best-selling handsets in the third quarter were optimized for messaging and other advanced Internet features.”

The top handset models in rank order, based on unit sales in Q3, were as follows:

• Apple iPhone 3G
• Motorola RAZR V3 (all models)
• RIM Blackberry Curve (all models)
• LG Rumor
• LG enV2

When it comes to the specific features that motivated U.S. consumers to purchase their handsets, 43 percent of handset buyers cited the need for a camera and 36 percent noted the ability to send and receive text messages. Mobile phones with a QWERTY keyboard experienced the greatest year-over-year rise in sales; 30 percent of handsets were sold with this feature in Q3 2008, versus just 11 percent the year prior.

“A growing data divide continues in cellular handsets,” Rubin said. “Those who see the value in wireless Internet access are justifying the investment, whereas voice-centric users have little incentive to upgrade, which is obviously detrimental to operators who seek to sell data plans and media-access services to their subscribers.”