Yeah, as above. Once you've registered the code (don't know about the PC but on the PS3 you go to Account Management>>Redeem Codes from the Playstation Home Screen and enter the 4-4-4 code), you restart the FFXIV Client (it asked me to confirm I was connecting this account to my PSN account) and once you've logged in the items are waiting in your in game mail, which you can pick up from any delivery Moogle.