OK, I thought about it. One issue is that Cingular in central Mississippi is both 850 MHz and 1900 MHz. I believe that a 1900 MHz phone will work OK but I'm not 100% sure. The CX65 has only 1900 MHz for the US.
Suggestions:
1) Go to
Pharos International and buy the "O2" prepaid. This SIM has a flat 14c/min rate which includes international calls to UK. It comes with 50 mins, so you might want to add a top-up to the order.
2) Buy a T-Mobile SIM on eBay and set up a dial-thru account with either GorillaMobile.com or VoiceStick.com (Jackson is in the 601 area code) for the long distance.
3) Walk in any Walmart in the Mississippi and buy a Simple Freedom phone and use an international long distance calling card.
I looked at BeyondWirelessGSM.com but they didn't seem to understand that anything existed beyond the borders of the US. Has anyone tried to get the to ship international?