it will be locked, no contract only means u dont have to stay with cingular for a certain amount of time, you can cancel anytime or do w/e. i belive cingular will send you the unlock code after 3 months of being a loyal customer. so if you sign up for the contract and they give you the unlock code and you cancel your cingular account, you will probabbly get charged those extra 200 dollars that you got disscounted, so either way they get their money.
anyway i dont kno y u need it unlocked but if it is for overseas travel cingular will unlock it. or if you want to go for a different provider like t-mobile then if you didint get the contract and they send you the unlock code you are good to go.