Apple incessantly insists that its admittedly successful iPhone is the be-all, end-all of the smart phone world. But reality is increasingly getting in the way of the Cupertino company's boasting, as most recently exemplified by a stunning new statistic about the real leader in the smart phone market: Google's Android OS is the platform installed on about 50 percent of all smart phones sold worldwide.According to the market researchers at Canalys, Android smart phones accounted for 48 percent of all smart phones sold in the second quarter of 2011, an all-time high for the still quickly-growing system. Android commanded just 33 percent of the market 6 months earlier, Canlys says, when at the time it surpassed Nokia Symbian to become the best-selling smart phone platform. Android OS sales were up almost 380 percent year-over-year, Canlys says.In some markets, Android is the overwhelming favorite. The OS owns 85 percent market share in South Korea, for example, and 71 percent in Taiwan.Apple ranks second in Canlys' estimates, with a market share of 19 percent on unit sales of 20.3 million. Still, iPhone sales are less than the half that of total Android sales, and the gap between the two is actually growing month-over-month. But Apple's iPhone is still the fastest-selling smart phone model overall, beating out a large army of Android devices from a variety of handset makers and wireless carriers.Number three Samsung almost beat Apple this quarter with over 17 million units shipped but had to settle for third place. Samsung did surpass Nokia, which as recently as late last year was still the world's largest maker of smart phones. That firm is sinking as fast as seems possible, with dramatically declining sales. (Nokia is, however, still very popular in emerging markets, a factor that could be key for future growth.)Windows Phone barely registered in Canlys' estimates: Microsoft's still-new mobile OS accounted for just 1 percent market share on unit sales of 1.5 million for the quarter, down 52 percent year over year (when the previous OS version, Windows Mobile, was still in market). On the other hand, I'd point out that Apple's publicly stated goal for the first year of the iPhone was 1 percent market share, and Microsoft, um, achieved that in just 9 months.Total smart phone sales in Q2 2011 were 108 million units, according to Canlys, which works out to growth of 73 percent year over year for the industry.