Due to the spammers this thread shall be link free.
Also, there are some models that must be Jail Breaked to unlock. I'm sure you know why so I won't bore you with all the prior discussions.
"Only your carrier can unlock your iPhone." is the OFFICIAL ANSWER!
I was given an Apple Smart phone but it's been locked. I would like to upgrade from my flip phone with Verizon but I need to learn what cables to buy for it and then get it unlocked. Is this possible?