I don't even have a passport currently. If I did travel, I'm more likely to buy a throwaway cell with a different account and add the number to my google voice account dialing...
If you're stuck in rural US, then you should use Verizon for it's older CDMA networks. Spending extra money and going through the hassle of getting another phone while traveling is a personal preference it seems, but for people who do travel it's one less thing to worry about.
CDMA is going away. Verizon is supposed to drop 3G by end of this year.
I'll believe it when it happens since Verizon is only leasing the towers in rural areas. Also, just how many accounts on HN do you have?