i understand that you can buy unlocked GSM phones but what i don't understand is how i could use one if my service (cingular) uses a SIM card? instead is there some code that uses my SIM card as without actually physically putting it into a phone?
Ya all you would need to do is take the sim card out of your current phone and put it in the unlocked phone you get. All your numbers and other files will be right on the new phone.
I've never really screwed around with them I saw my buddy test out a prize phone for a namco prize and it worked just fine after he put his simcard in it.
Never tried putting mine in my computer to see what alls on it but one would believe you could modify it but with technology you would think something would flag as soon as you use it.
Most phones can be unlocked, some need their firmware updated and others just need an unlock code. You can also get proper boxes to do them with.
They all do the same job tho like dude se said, they allow you to use any network on your phone. Your normally locked to a certain network, when you take out a contract.
...unless you get an 02 phone and they are usually unlocked ... well not all the newer ones but most are. gsm is simply a type of network which the phone providers use. it has different frequencies.
A lot of UK phones now come unlocked, in my experience they have anyway, the last 4 phones that I have had have all been unlocked to any network although they were contracted to O2 and vodaphone.
In regards to the SIM card, it will not transfer all your information, it can only hold a certain number of phone numbers and text messages thats it.
Although most phones these days can be backuped on the pc using a usb cable.