Apple has clawed back US smartphone market share from RIM's BlackBerry this past holiday, comScore found in a new study. Between September and December, the iPhone's share grew over a percent to 25.3 percent while the BlackBerry dropped by nearly an identical amount to 41.6 percent.

Neither change is directly explained by the analyst group, though comScore pointed out that the use of apps, music, social networking and web browsing increased over the same period, all features that play into historical strengths of the iPhone.

Android also made significant strides in the three-month span. The launch of the Droid, as well as lower-key releases like the Behold II and Cliq, led Android to more than double its share to 5.2 percent. Palm, however, dipped noticeably from 8.3 to 6.1 percent, while the aging Windows Mobile OS fell exactly one point to 18 percent.

Smartphones continue to play a small role in the US as Motorola remains the top firm in the US for absolute cellphone market share, having dropped slightly to 23.5 percent. Most others made only subtle gains or losses with LG and Samsung nearly even at 21.9 and 21.2 percent, Nokia at 9.2 percent and RIM at 7 percent.