The very much anticipated Ultrasn0w carrier unlock is now available for the iPhone 4. Simply search for it in Cydia and get going!
We’ve heard that 3G is still not supported on T-Mobile USA so be sure to disable 3G in the network settings of your iPhone. If you don’t see it in Cydia try adding the repo: http://repo666.ultrasn0w.com.
FTC: We use income earning auto affiliate links. More.