Apple's iPhone 3G has "dethroned" the Motorola RAZR as the leading handset purchased by adult consumers in the US.

The iPhone 3G overtook the RAZR during the third quarter of the year, according to market research firm NPD.

This marks an end to the RAZR's 3-year run in the top slot, falling to second place, followed by the BlackBerry Curve, LG Rumor and LG enV2.

"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."