I have successfully unlocked my T-Mobile G1 for free? How you ask? After 90-days, T-Mobile allows you to unlock almost any phone you have purchased from them with the T-Mobile branding, and all for FREE. The process can take about 2 weeks (as it did for me), but it worked. Here is how:

Call T-Mobile on 1-877-453-1304 from another phone (not your G1). I got that number from their Contact page Its the standard voice prompt thing, so say English, enter your G1’s phone number, then when they ask what you want help with, say the magic word “Agent” Then they ask what you would like to talk about, and say “SIM Unlock Request” My experience with T-Mobile has been pretty good, within a minute I was talking to the real person. At this point, you verify your identity, and explain to them you want to unlock you phone because you are going overseas and want to use another SIM card. They will ask you for you phone’s IMEI number. This is a sacred number, so be careful who you give it to, as you can report the phone stolen, give them the IMEI number, and have the phone permanently disabled. You will find the number: on the side of the box your phone came in, on the G1 itself under Settings –> About phone –> Status, or by dialing *#06# Give them your email address, and within 14-days, you will get an email from T-Mobile with your unlock code. To unlock the phone, power it off, insert a non-t-mobile SIM card, and power it back on At the prompt, enter the unlock code from the email and you’re done! The reason for writing this post is I had no idea this could be done for free with any T-Mobile phone after 90-days has past. There is no need to pay $25 to any scam site, just do it legit, for free, and without issue.