i am in CA, USA, using 3gs 16g iPhone with T-mobile service, after jailbreakme.com (JB), then unlock with ultrasn0w. My phone can be use now. phone call, MSM text message... everything works fine, but remember after you unlock, DO NOT install T-Mobile US - Postpaid/F... 1.0.11, it will cause you freezen and may need to restore again. this is my experience. well i am not really worry about JB and unlock do all over again, but need to get a att sim card from friend AGAIN.... this is hardest part