I went to Half-Price Books to see if I could get rid of the $5 or so I have left on a giftcard. When I paid, I forgot about the card and used my own money.
Oh well, it was only $3.
If you're interested, I bought Rattling the Cage by Steven M. Wise, an exploration of the argument for giving chimpanzees and bonobos legal rights. Funnily enough, I thought I was buying the book that is actually titled Drawing the Line, but that's OK. I'll find that one some other time.