Microsoft fans, start your engines. It’s been a long time coming but today it’s finally here… Windows Phone 7 handsets are now available for your purchasing pleasure in the U.S. Microsoft launched its new mobile OS last month in Europe and we’ve had to sit and wait impatiently as our friends across the pond dangled their Windows wear in our faces. Well, not any more â€” the HTC Surround, Samsung Focus and HTC HD7 are already available for purchase and the Dell Venue Pro is rumored to drop later today. The LG Quantum is also available for pre-order from AT&T starting today. Expect to pay $199.99 for any of the aforementioned Windows Phones, though better deals are available through the likes of Amazon.com, as is often the case.