Existing Orange Pay as yo go customers ONLY.
Go to carphone warehouse shop.
Pick your phone.
Tell them at till you have an orange pay as you go phone.
They check your phone number.
You just pay for the phone.
Therefore you don't have to buy £10 credit on a different phone number or change your number.
This is not really a great money saver but its a hastle saver as you don't have to inform all your contacts of your new number.
Was told this at to different carphone warehouse shops.