Hacked Hardware

Up until now in Hong Kong, I've used a very cheap cel phone, quite thick, not a lot of features and generally outdated. But yesterday, Sunny, my coworker, worked some hacker magic and somehow unlocked my TMobile phone that I use in the states. I am now recieving calls to my HK number with my US phone. As a bonus, it's not a contractual thing like in the US, I pay as I go.