Windows Phone 7 phones are today available in the US, as Microsoft begins its campaign to break up Android and iOS's party. The HTC Surround and Samsung Focus are both available to buy through AT&T, while T-Mobile offers the HTC HD7 device.

Already, there's a lot of Windows Phone 7 software around, including official offerings from Twitter and Facebook. The Marketplace is home to other popular favorites, including Shazam, Netflix, Tetris, and IMDb.

If you want a feel for what the new Windows Phone 7 operating system is like, then go check out our guide to using the Windows Phone 7 emulator, and watch our video demo.