i have a unlocked blackberry 9780 activated on t-mobile, im going to dominican republic and i would like to know if i can activate bis there with their network and when i come back to new york it wont interfere with my t-mobile service
yes you can i do this all the time. the service books will automatically load into the phone when you switch sim cards. the only thing you have to do is switch the apn settings manually to get some programs to work. if you dont want to switch it you will still be able to browse the internet and use your messaging apps but you might not be able to use applications that do streaming. i also recommend you use ORANGE instead of CLARO or VIVA because with ORANGE your phone works with 3G coverage while with CLARO you only get EDGE and VIVA only has GPRS. only at&t phones get 3G with CLARO. here is an xda forum link with the settings you need.