I don't believe in breast enhancement pills either.
Some research has been done into them and, whilst they claim that they may work (they use a plant extract which is similar to oestrogen which apparently "tricks" your body into thinking it's pregnant and therefore breast growth) but they are not reccommended as the safety of the herbs in the pills isn't certain and the long term effects of photo oestrogens is unknown.
What is wrong with your own breasts? Have you had children? If not they change alot during pregnancy and breastfeeding etc...