I do the same thing WCK4 does, I have a unlocked T68 that I use overseas on AT&T. I pop my SIM out of my us phone and I'm all set to go. Verizon makes that a bit different since they don't really offer GSM over here, but you can just pick up a SIM once you land and pop it in and let people here know your number.
I also recommend getting a calling card, it's way less exensive then some other options are.