Windows Phone 7 handsets are now available for purchase in the U.S. Microsoft launched its new mobile OS last month in Europe. The HTC Surround, Samsung Focus, HTC HD7 and Dell Venue Pro are already available for purchase. The LG Quantum is also available for pre-order from AT&T. Expect to pay $199.99 for any of the aforementioned Windows Phones, though better deals are available through Amazon.com.