Just thought I'd share this tidbit of information...
I was in the Dominican Republic earlier this month on vacation. I'd brought my Tracfone with me thinking it wouldn't work. When we arrived Punta Cana, my friend tried calling home with her brand new Razr post-paid Cingular phone. She was furious when it didn't work because she'd called Cingular the week before to ensure that it would work.
I tried by little Motorola v60i and it worked! In fact, I used it often during the week to call home and the coverage was fabulous.
I have read of TracFones working in other countries, where the frequencies are compatable, and your underlying carrier has roaming agreements. However, when the foreign carrier charges your carrier for the usage, you may get a notice from TracFone, and have your service cut-off.
I used my Nokia 2126i in Freeport, Bahamas when I was there at the beginning of August. It was using analog the whole time, I guess there's no digital there. My service never got cut off either. I used it quite a few times. Now I have a GSM phone and moved my number to that phone. I wish I had a GSM phone at that point to see if it would get shut off. My sister had her Cingular phone and it got a signal, but she wouldn't use it because of roaming charges.