According to Nielson, iPhone 3G takes number one spot with 4% of ‘embedded base of all subscribers’, with RIM chomping on its heals.

Top 10 Mobile Phones in Use (U.S.) – January -October 2009
RANK Device Embedded Base of
All Subscribers
1 Apple 3G iPhone 4.0% 4.0%
2 RIM BlackBerry 8300 Series (Curve, 8310, 8320, 8330, 8350i) 3.7%
3 Motorola RAZR V3 series (V3, V3c, V3m, V3i, V3i DG, V3) 2.3%
4 LG VX9100 (enV2) 2.1%
5 LG Voyager 1.7%
6 Samsung SPH-M540 (Rant) 1.5%
7 RIM BlackBerry 9530 series (Storm) 1.4%
8 LG VX9700 (Dare) 1.3%
9 LG Vu series (CU915, CU920) 1.3%
10 RIM BlackBerry 8100 series (Pearl, 8110, 8120, 8129) 1.2%
Source: The Nielsen Company