Let the hive mind of Engadget get that for you.
"I just switched to Sprint from Verizon about three months ago for the Pre. Then I went for the Hero about a week ago. Now, I miss my hardware keyboard and am thinking about switching to the Moment. I am still able to switch back to Verizon if I want and get the Droid when it arrives. Should I just trade up to the Moment when it comes out, see if I like it, and if not switch to the Droid? Or something else entirely? Help!"
But it will work in Peru(CDMA), Brazil (CDMA & GSM), Venezuela (CDMA & GSM), French Guyana (GSM), Uruguay(GSM), and Suriname(GSM).
Argentina, Ecuador, and Bolivia are a no go though.. weird.