According to a report released today by wireless research group, NPD, the iPhone 3G is now the leading handset purchased by adult consumers in the US. Apple's smartphone surpassed long-time leader the RAZR for the third quarter of 2008--Motorola's handset has held the title of top handset for 12 quarters.

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

The top five is rounded out by the Blackberry Curve and two LG handsets--the Rumor and enV2.

Despite the iPhone's surge in popularity, NPD reports that the sale of domestic handsets has dropped 15-percent from the quarter before.