Hello. As you can see, I have several questions about unlocked cell phones. Please enlighten me.

1. What are the benefits?
2. Can only phones that use a SIM card (i.e. GSM phones) be unlocked?
3. How can you tell if a phone is locked or unlocked?
4. If you unlock a phone, can/will the carrier automatically lock it again?
5. Let’s say I buy an unlocked phone off eBay. Then what?
6. From what I’ve read on Google and Wikipedia, having an unlocked phone is good if you travel. Why?

I live in the USA and Verizon Wireless is my mobile phone carrier. I do travel out of the country a fair amount, but I’ve been able to manage fine with phone cards (have to use a land line each time, though).

If I had an unlocked phone and I flew to Mexico, what would I need to do to use it there? Could I make only local calls? Or could I call back to USA? Do I buy a SIM card there or something?

the blackberry phone