So I bought the phone from TigerDirect (http://www.tigerdirect.com/applications/searchtools/item-details.asp?Edpno=3438639) and it seems like it's not unlocked because when I put my SIM card in, it says "Insert right SIM card."

I called AT&T to see if they would give me the unlock code but they said that is wasn't the "original customer" of the phone so they couldn't.