NEW YORK ( TheStreet) -- American consumers know they want smartphones, but are still mostly clueless about the software running them.Just as Apple ( AAPL) launched its iOS 4.1 for the iPhone earlier this week, a study from Forrester Research ( FORR) found that nearly half of American smartphone owners don't know what operating system their phone uses. Of the more than 30,000 smartphone users Forrester asked about which brand of phone they owned, which features it includes and whether it runs Google's ( GOOG) Android or Microsoft's ( MSFT) Windows Mobile operating system, 48% got the operating system wrong. That number includes 13% who said their phone used both and roughly 18% of Research in Motion ( RIMM) Blackberry users and iPhone users who credited Android or Windows with running their phones. With Verizon ( VZ), AT&T ( T), T-Mobile ( DT) and Sprint ( S) each supporting four smartphone platforms or more, multiple manufacturers including Motorola ( MOT), Samsung and HTC producing Windows and Android phones and mobile applications growing into a $6.7 billion industry encompassing 4.5 billion downloads, according to Gartner ( IT), the potential for confusion is high. If Blackberry devices and the RIM OS were still leading in mobile market share with Apple following behind -- as ComScore ( SCOR) reported in May when RIM held a 41.7% share to Apple's 24.4% -- the situation may not seem as dire. Apple and RIM have proprietary holds over their hardware and software that makes it difficult, but apparently not impossible, to mistake the two. Since the NPD Group reported in August that Android phones had surged to a 33% market share compared with RIM's 28% and Apple's 22%, though, a different set of problems has emerged. There's a reason Google has place its Web and mobile development on equal footing, Microsoft scrapped and rewrote its entire mobile platform for Windows Mobile 7, H-P ( HP) paid $1.2 billion for Palm ( PALM) and its WebOS and Nokia ( NOK) teamed up with Intel ( INTC) on its MeeGo OS to replace the Symbian OS (which still has 41% of global market share): Mobile matters. It's why Google's Android grew from 1.8% global market share in August 2009 to a more than 17% share today and why Gartner expects mobile applications alone to account for $29 billion in global revenue by 2013.