I am considering buying an unlocked international HTC Desire from Amazon. I plan to use my AT&T sim card, here in California. Here are the specs of the device as listed on Amazon. Quad-Band Unlocked GSM cell phone compatible with 850/900/1800/1900 GSM and 900/2100 3G frequencies plus GPRS/EDGE capabilities Does anyone know if this device will be able to access the AT&T 3G network here in the United States? Thank you.