Microsoft installed a gigantic Windows Phone in New York’s Herald Square Monday to mark the debut of Windows Phone 7.5 devices on store shelves.

The smartphones available from AT&T include the US$199.99 Samsung Focus S, which has a 4.3-inch screen; the $49.99 Samsung Focus Flash, which has a 3.7-inch screen; and the HTC Titan, which has a 4.7-inch screen. HTC's Radar 4G has a 3.8-inch screen and is available on T-Mobile's network for $99.99.

The event in New York City included a performance by Far East Movement as Microsoft continues to go to great lengths to spread awareness of the Windows Phone OS. The company also said that it’s taking steps to align the smartphone OS with its future tablet and PC operating systems. Microsoft wants to bring similar user experiences across Microsoft-based phones, PCs and tablets to make usage consistent and easier.

What’s called the Metro interface will bring a radically different look to Windows 8, with live tiles and touch-based gestures replacing icons and mouse clicks. The idea is to make accessing programs and content easier than previous versions of Windows, which required going through nested menus and folders.

With reporting by Agam Shah in New York, Nick Barber, IDG News Service.