The only reason you would need to unlock a phone is to use it on another carrier's network. If you won't be changing carriers, then you don't need to unlock it.
There are businesses out there that will provide unlock codes for a fee, but you need to shop around for reputable people/businesses.
Just call, they won't jump through the phone and strangle you, I promise. I called AT&T to get the unlock code for my Bold, after I had canceled my AT&T contract - I wanted to use my Bold on T-Mobile. They gave me the unlock and even asked if I needed assistance it unlocking my device. I told him "no", as I already had instructions but I thought that was awesome. The point it, just call your provider. I've hear mixed results but worst case scenarios is they'll give you some bs story about why they can't and the you just go buy the unlock code.
there is a thread on how to get to the unlock screen in the faq section
i unlocked my tmobile curve
it was basically getting to the screen and then typing in the code
thats it
Just follow the directions. After you put in the code, under the MEPD menu that you are at, Network should not say active. I believe it should say disabled. That is how you know it went through.