If you buy a T Mobile contract phone from the Carphone warehouse, be careful, their 14 day return policy does not apply to T Mobile phones.
I went back to the store after having a phone for 18 hrs and they would not accept a return (all I wanted to do was to go to O2).
If you are unhappy they will then try and sell you an insurance policy which allows you to cancel your contract. You have to have the contract for a certain amount of time for the policy to kick in.
Please think before you buy, and don't fall in to the same trap I did. :thumbsup: