By Anne Kates Smith, Executive Editor February 1, 2011 As you wrap up another year of gift returns and exchanges, contemplate a patent that was granted last November to Amazon, the online superstore. The invention? Technology that automatically trades gifts you've indicated that you don't want for gifts (or a gift certificate) that you do. You could block everything you receive from Aunt Mildred, say (she wouldn't have to know), or convert books about healthy living to something more decadent on your wish list. No word from Amazon if or when the gift converter is scheduled to go live.