I had been looking through the forum for a way to unlock my Sony Ericsson w580i and found more threads than I could count. I was directed to sites to purchase the Unlock code, but after checking several reviews on those sites. I gave up and called AT&T (my provider) and asked to have the codes for both my phones.
They gave them to me for FREE!!!! Then they sent me an e-mail on how to use the codes. FREE!!! So call them first.