The Nielsen Company reported Monday that smartphones now account for 28% of the cell phone market in the United States. Nielsen’s report also states that 41% of cell phones purchased in the U.S. over the past six months were smartphones. In terms of smartphone OS share, Nielsen paints a very different picture compared to earlier data presented by the NPD Group and Canalys. Nielsen’s data shows RIM still at the top of the U.S. smartphone market with a 30% share. Apple sits at number 2 with 28% and Android follows with only 19% of the market. Reports from NPD and Canalys released just this morning, however, show Android passing BlackBerry OS and attaining a commanding lead in the U.S. while iOS and BlackBerry OS battle for the two and three slots. Both firms claim that Android now holds a massive 44% of the U.S. smartphone market, while iOS is number 2 with 23% – 26% and RIM’s BlackBerry OS is number 3 with 22% – 24%.