It has always been my understanding that there are two options when a baby bites you while breastfeeding:
Option #1 - My sister-in-law, Ditte, taught me to flick the baby in the mouth with my finger.
Option #2 - La Leche League taught me to put the baby on the ground if he or she bites you. A baby obviously isn't hungry if he is biting because it is impossible to nurse and bite at the same time.
Well... meet Option #3: