Why Unlocked Phones Don't Work In the US
schnell writes "Unlocked cellular devices have long been a part of the wireless landscape in Europe and elsewhere. But longtime industry analyst Andrew Seybold explains why that model doesn't work in the US due to technology and frequency differences, and why LTE adoption may not make things any better."
actually there is an older mini usb and a newer micro usb,
Mini usb on the left, micro on the right.
http://www.usb-mobile-charger.com/wp-content/uploads/2009/07/mini-micro-usb-connector.jpg