if it was made in 2002, it's probably bluetooth.
That said, if i'm wrong and there is an actual phone in there, it should be possible to unlock it. You can just call the service provider after a while and just tell them you're going out of the country and you would like your phone to be unlocked. They'll usually give you an unlock code. Then you just put in your other sim and insert the unlock code when prompted. Even better that you're in Europe. USA has too many laws protecting companies from catering to their consumers.
However, if the phone is GSM and you want to unlock it another mobile standard, say CDMA, this is impossible.