Does the Verizon iPhone 5 use a SIM card (for voice, 3G, 4G)?

Here's a rather intricate question. I'm trying to decide between a Verizon or AT&T iPhone 5. Currently, I've enjoyed my AT&T iPhones, but Verizon has better 4G coverage where I live.So, the 4G would be nice to have, *but*… I also travel, on occasion, and my current iPhone is carrier-unlocked. Since it's a GSM phone, it uses a SIM card, so I can pop in a SIM card for whatever country I'm visiting and I don't pay horrendous roaming charges.

This has always been the deal-killer for the prospect of getting a Verizon phone, since they haven't used SIM cards. However, I hear that Verizon's 4G phones *do* use SIM cards, but some of the comments I've read indicate that the SIM is *only* for the 4G data radio, and that voice and 3G still use the hard-wired phone ID stuff.

So, my questions are:
1 - Does the Verizon iPhone 5 even have a changeable SIM card *at all*?
2 - If it has one, is it only for the 4G feature, or can we *finally* (provided that the phone is carrier-unlocked) just swap in a different SIM card in another country and make voice calls and use 3G data without those using Verizon?

Yes, it uses nano sim card.

Verizon world phones (including the iPhone 4S and5) do use a SIM but it's ONLY for international roaming. Unfortunately it's locked to the Verizon network and even if you managed to unlock the phone, it would only work outside of the US with a SIM supplied by Verizon.

An unlocked AT&T phone on the other hand will accept any SIM and function world wide. The only potential problem will be with Internet access where you *may* have to change the APN settings to those required by the carrier. You can usually research that on line (just google "APN" and the name of the service provider) or copy the settings from a phone that is already working on that system.

Hopefully Verizon and Sprint will continue their unlock tradition with the iPhone 5. For the iPhone 4S, Verizon would unlock your device so you could use local SIM cards while traveling abroad if you were in good standing (customer for 60-days or more). Similar with Sprint. Some articles include some pretty detailed instructions of how Verizon did this and that they were able to use another SIM (not the Verizon Global Traveler SIM) after it was unlocked. The iPhone 5 uses a nano-SIM, so overseas carriers would also need to be able to provide that form factor.