Research in Motion sold the most smartphones in the United States for the first quarter of 2008, more than doubling the nearest competitor's market share, an IDC report found.

The report found RIM grabbed 44.5% of the market for the first three months of 2008, up from 35.1% in the previous quarter.

RIM has successfully been able to broaden the appeal of the BlackBerry to more than just professionals, said IDC analyst Ramon Llamas. With new consumer-friendly devices like the BlackBerry Thunder and the BlackBerry Bold, RIM is well-positioned to be a strong presence in the "prosumer" segment.

Apple's iPhone came in second place with 19.2% of the market in the first quarter, a drop from 26.7% the quarter before.

One reason may be that the fourth quarter included the holiday shopping season. More recently, consumers may be wary of purchasing an iPhone when there's reportedly a 3G version right around the corner (although, there's a report of a delay).

Palm found itself in third place with 13.4% of sales, up from 7.9% in the fourth quarter. One key factor was the release of the Centro in February, IDC said.

Samsung was in the fourth slot, with 8.6% of the market, up from 5.1% the previous quarter.

Things weren't as positive for Motorola or High Tech Computer. Continuing on a downward trend, Motorola dropped from 7.5% share in the first quarter to 2.6% in the first. HTC's share fell to 4.1% from 7.9% in the previous quarter, the report found.

IDC did not reveal the total number of smartphones sold in either quarter.