Apple's iPhone and smartphones based on RIM's BlackBerry operating system are tied with 27 percent of U.S. smartphone market share, according to October data from the Nielsen Company.
Google's Android operating system commands 22.7 percent of the U.S. smartphone market, Nielsen reported from a survey of 4,900 users.
However, mobile-phone users who are upgrading to a smartphone next year indicated that Apple's iOS and the Android operating system were their most likely choices.
Some 35 percent of current smartphone owners said they would pick an iPhone, while 28 percent of smartphone and feature-phone owners said an Android handset was on their wish list.
Thirteen percent of smartphone users said they were not sure what device they wanted, while 15 percent would pick a RIM Blackberry model.
While RIM remains in a statistical tie with Apple, the trend toward Apple iOS and Google Android handsets can only be disheartening for the BlackBerry maker, which has long enjoyed 40 percent-plus market share in the U.S.
Only 5 percent said they would choose a Windows Mobile smartphone, which doesn't bode well for Microsoft's latest Windows Phone 7 platform.
Desire for Apple's iPhone was greater than Android and all others among those aged 18 to 24, 25 to 34, and 55 and older. Interestingly, those aged 35 to 54 were slightly more apt to pick and Android device.
Also, out of 9,200 respondents, women were more likely to choose an iPhone than an Android phone (31 percent to 22 percent), while men were more likely to choose an Android device over an iPhone (33 percent to 29 percent). Verizon Wireless's masculine marketing campaign for its Droid smartphones clearly contributed to this scenario.
Royal Pingdom meanwhile crunched its own mobile OS numbers using Web traffic data from StatCounter. The researcher found that, while Symbian leads in mobile market share worldwide (thanks to Nokia), iOS is pretty much blowing away the rest of the competitive field, leading in more than 30 countries.
In 21 of those countries-including Canada, Cuba, Switzerland, Australia and Ireland-more than 50 percent of the mobile Web traffic came from iPhone or iPod Touch.
By contrast, Android accounts for more than 50 percent of the mobile Web traffic only in South Korea. That's home to Samsung, which makes a number of leading Android handsets as part of the Galaxy S line.