For those of you wondering:
I was in cancun last week. I activated the international dialer on my cell phone (No charge) by calling verizon before i went. I used my phone while in Cancun (just dialed 001 before the area code and number) and it worked perfectly. Just as clear as if i was in the states.
My billing period happened to just end, and i just got the bill. My calls were billed at $.85/minute. I think it was a great deal for the convenience of using my own cell phone anywhere! These were for out-going calls. I did not take any incoming calls but i have heard from others that those are cheaper, but i cannot verify. HOpe this helps!