My older son bit me exactly three times - first time, I took him off, said no, and put him in his crib. He did it again about a week later, to make sure I meant it, and I did the same thing. The third time, the doorbell rang and startled him, and he got this panicked look in his eyes, and I continued to nurse him. I nursed him til he was about 14 months old.
DS #2, however, was completely different. Even though I did the same thing with him, his personality is different (not a rule follower, more of a rule breaker) and he continued to nip on a regular (weekly) basis until I stopped nursing him at exactly 12 months.