Market researchers at Gartner said today that the worldwide mobile phone market grew by 17 percent in the first quarter of 2010, with 315 million units sold. But smartphone sales grew even faster, by 49 percent, with 54 million units sold in the quarter.

And when you drill down into those numbers, you see some interesting trends. Key among them is that Google's Android system is showing the biggest gains. It outsold Microsoft's Windows Mobile by a wide margin in the last quarter.

A year ago, Windows Mobile controlled 10 percent of the market, good for a fourth-place finish behind Symbian, Research in Motion (RIM), and Apple. And Android, which accounted for a scant 1.6 percent of the market, came in fifth.

This year, the positions are reversed. Android, now in fourth place, controlled 9.6 percent of the market, while Windows Mobile has fallen badly to 6.8 percent of the market.

The other players saw a bit movement as well. Nokia's Symbian, still the number-one overall smartphone platform worldwide, fell from 49 percent of the market to 44 percent. BlackBerry maker RIM held steady at 19 percent, down from last year's 21. And Apple's iPhone jumped from 10.5 percent of the market to 15.4. (Note that last year, Windows Mobile and iPhone were neck and neck; today, the iPhone has over twice the market share of Windows Mobile.)

It's unlikely that Apple will surpass RIM this year, but it could do so by 2011 if the BlackBerry maker doesn't turn things around. But even more dramatic, perhaps, is Android's rise. Android has already surpassed iPhone sales in the United States—its growth in North America was a whopping 707 percent—and could do so on a worldwide basis soon if it maintains this growth trajectory.