Guidance Selling Brand New 3GS, Keeping it Unlocked?

[-ND4SPD-]

I'm just looking for some guidance here so I do this correctly since I'm a bit of a newb when it comes to this stuff.

My current 3GS is damaged & will be replaced under warantee (already verified this with an Apple Store Employee). I'm also eligable for a free upgrade (besides an $18 fee) through AT&T for an iPhone4 (which I really want for the improved camera ability).

I'm wanting to get a replacement 3GS & sell it un-used. Do I need to do or tell them anything specific while at the Apple Store to ensure it's unlocked & ready for any carrier the new owner chooses?

I'd normally wait till June for the new model iPhone to be released but with the holidays coming up & the rumored release of a Verizon iPhone, seems the market would be better sooner than later. Thanks in advance for the help!

 

[sting7k]

If you get an iPhone in the US it is locked to AT&T. You would need to jailbreak and unlock it yourself.

 

[-ND4SPD-]

Got it, I was thinking that it didn't get locked until it was activated.