Microsoft built a six-story Windows Phone in New York's Herald Square to launch a batch of new HTC and Samsung phones running on the Windows Phone 7.5 (Mango) operating system. The Big Windows Phone structure featured two stage areas in between the huge screens - one to demonstrate the Music+ Video Hub with a live performance from electro hip hop group Far East Movement and the other to represent the Xbox LIVE gaming experience with a game of Plants vs Zombies using real people as the characters. As for the phones themselves - HTC's Radar 4G is available now on T-Mobile, while HTC's TITAN and Samsung's Focus S and Focus Flash head for AT&T.;

Microsoft says that its new Windows Phone operating system is all about connecting people and as if to prove the point, the Big Windows Phone - about 150 times bigger than the real thing - kick started the launch day by playing host to a cutesy wedding proposal from New Yorker Yuriy Rud to his suitably stunned girlfriend (she accepted, by the way). In addition to live music and an epic battle between the undead and some overly protective flowers, the huge screens in front of the stage areas in the super-sized smartphone also slid back to reveal a live game of Fruit Ninja, complete with real fruit and a sword-wielding martial artist.

Of course, the event was staged to showcase the new Mango phones - all of which feature front- and rear-facing cameras, powerful processors, bright, colorful screens with a resolution of 480 x 800 pixels, and are capable of 4G speeds.

Leading the charge is Samsung's 8.55 mm thin Focus S, which has a 4.3-inch Super AMOLED Plus display boasting a 16 million color palette, a 1.4GHz processor and an 8 megapixel autofocus camera with LED flash and 4x zoom on its rear, and a 1.3 megapixel at the front. The smartphone is said to be good for up to 250 hours of battery life on stand-by and 6.5 hours of continuous talk time, and is available on the AT&T network for US$199.99.

Also on AT&T, the Samsung Focus Flash is available for just US$49.99 and features a 3.7-inch Super AMOLED screen, a 1.4GHz processor, a 5 megapixel autofocus camera with LED flash and 4x zoom, and is capable of 720p video capture and playback.

Taking a quick diversion to T-Mobile, HTC's Radar 4G has been constructed from a single piece of polished aluminum, and features a 3.8-inch screen, a 1GHz Qualcomm processor, a rear-facing 5 megapixel camera with LED flash and low-light-friendly BSI sensor and a VGA-quality camera at the front. This one is priced at US$99.99 (after a US$50 mail in rebate).

HTC's impressive 9.9 mm thin TITAN smartphone will be added to AT&T's portfolio shortly. It has a 4.7-inch screen, a 1.5GHz processor, is capable of recording 720p video, has an 8 megapixel camera with dual LED flash and F2.2 lens, and also features a BSI sensor. There's also a 1.3 megapixel camera at the front and SRS Audio enhancement.

Highlights of Windows Phone 7.5 include Internet Explorer Mobile with a new Local Scout function that offers restaurant, shopping and event recommendations, the grouping of communication portals together in one place - such as email, SMS, social media, chats, and Windows Live instant messages - and a catalog of over 35,000 apps and games from Windows Phone Marketplace, including the new Spotify on-demand music service app.

Take a quick look at the following time-lapse video of that crowd-stopping Big Windows Phone being constructed: