Google’s Android operating system is going from strength to strength and if the latest figures from Nielsen and IDC are to be believed, the OS is starting to dominate the smartphone market.

IDC reports that Android commands a healthy 39 percent market share in overall smartphone sales this year. However, Nielsen has some even more optimistic figures and says Android phones grabbed 56 percent of the market in August.

Of course, the positive trend comes at the expense of other smartphone players, mainly RIM and Nokia. The share of Blackberry and Symbian phones keeps going down, while Apple’s share appears to be stable and Windows Phone 7 is growing, albeit slowly.

IDC believes global smartphone shipments in 2011 will hit 472 million units, 55 percent more than last year’s 305 million.