Cellunlocker.net - worked perfectly, great price!
unlocker code was emailed to me within minutes, but my new T-Mobile phone wasn't here at the time, so I didn't have a SIM card to put in my old ATT Motorola Bravo. I had spoken to a T-Mobile rep who told me that I could buy a SIM card for $3 (instead of use the Samsung Smart Gravity with a two-year contract that was due the following Monday - no UPS on Saturday) and use my old phone (a Motorola Bravo).
I had ATT for years and had finally gotten a smartphone (the Bravo). But
ATT finally ticked me off over the line and I switched to Sprint.
After 2 weeks, I had battery issues. I called Sprint, who sent me, in a van with an expiring transmission - 20 miles round trip, to a Sprint store only to be told that the store didn't carry batteries and that I had to get it online. After getting a Sprint manager and being told that I had to buy a replacement battery, after only 2 weeks (in a Samsung Transform Ultra phone) and then get a refund, I decided that Sprint wasn't who I wanted to do business with.
I went online and signed up with T-Mobile. Then I went online to see if I could find an unlocking code for the Bravo. When the phone got here this past Monday (Feb. 27, 2012), I used it (since yesterday). I thought that I would have to call T-Mobile and have them send another SIM card, but then, I thought, what the heck, I'll use the SIM card in the T-Mobile Samsung Smart Gravity in the ATT Motorola Bravo phone and see if the unlocker code works. I can always put it back in the T-Mobile phone, right?
I put the SIM card in the Bravo, started it, and entered the unlocker code and voila! It worked.
Good deal for $8 bucks for an unlocker code! Now I can return the Samsung Smart Gravity (nifty phone, though, but the Bravo has a slighly bigger screen and I was already familiar with it. Now I can get a cheaper monthly price and not be tied to a contract! Or get a unlimited plan for the same that I was paying for 500 minutes and 200Mb data! ($50 and tax, should be about $65 or less a month.
Sorry for the useless details, but I own a computer repair biz (started in mainframes in 1970 in USAF and got into microcomputers in 1983) and live and breathe details cause they help one see the total picture and that helps you see and intuit more solutions, knowing the big picture. ;)
Cellunlocker.net is the best (and I know the difference)