You can always buy Amazon gift cards through Gyft. You can always get gift cards for a bunch of other retailers. I recommend checking it out 
Ya I know, but it kind of defeats the purpose in my mind. I mean right now I buy bitcoins with cash. So if I wanted to shop with giftcards I could would just skip the bitcoin part and buy the giftcards with cash as it would save money and time.
...Now if I could only do that on amazon or at my local deli to buy beer, eggs, bread, and milk I would close down my Citibank account and go totally bitcoin. You hear me bitcoin DEVS, make it happen..... 
You can always invest in one of the several bitcoin debit cards that's available. In that way you can spend your bitcoin at your local deli. Bit-X and Xapo offers a card that is directly linked to your wallet [think there is others also] so you do not even have to 'load' the card beforehand, just swipe it and the amount comes off your wallet.