World traveler, are ya? You, my friend, need the new iCool G700. It looks like a Vertu candybar phone on the outside, but flip it open and hoo boy, there’s another phone that looks like a Motorola RAZR clamshell phone (except much fatter).
You’ll be able to use two different international GSM SIM cards. The phones share the same battery and can both be on simultaneously because they use separate boards.
Available in China (I think) for around 200 American dollars.
The Clamshell iCool G700 with Real Dual Mode [Slashphone]