I just bought a 7105T on Ebay that's locked to T-Mobile for my teenager who has an AT&T sim. (Stupid perhaps, but the phone is in fantastic condition and the price was right... And I know it's possible to unlock them.)
I know that T-mobile will send you an unlock code if you're a customer- which I'm not. I know the steps required to unlock them. What I'm missing is the all important 16 digit CODE. I assume these codes are somehow based on the IMEI & that there's not a "one code fits all" answer.
The question is: How do I get a code? I see pay sites that will email you the code but I much prefer the F-R-double-E way if possible.