errm o2 is not owned by BT, BT sold it off before it changed its name to o2...used to be called british cellnet - BT has its own limited mobile services in some areas...
I thought BT and vodafone mobiles were unlocked unway?...unless they started to lock phones to combat stolen phones...unless its a pay as you go?...why then I have no idea...
just to clear up some confusion

...not having a go or flaming
