C.M.
We also flicked the baby on the cheek and said, "No bites!" Worked great, within a couple days biting was entirely done. Some friends objected to 'hurting' the baby, but we were determined to nip that behavior in the bud, and found that lighter taps were useless. He needed an immediate and sharp indication that biting hurts.
He did go through a biting stage again around age 2, but was old enough to understand, "Absolutely NOT! That is DANGEROUS!" I bit him back once (yes, I was young and foolish), but decided that would just become a game and there was really no safe way to bite hard enough and not too hard, so we vetoed that plan. Immediate reaction, not necessarily punishment (because he didn't realize why biting was wrong, except when it hurt HIM) turned out to be the key to stopping this behavior quickly. Hopefully you will eliminate this bad habit before it causes any grief.