Though, I think placing the decimal point where it is was a mistake, in retrospect. If Bitcoin really gets popular, it will almost certainly have to be moved -- to the right! Though I don't think that will need to be considered seriously until 1 BTC = 10 000 USD.
Ideally you must have at least the cent a minimum currency value, unless the currency unit you operate with has no value, such as Indonesia Rupiah, which ain't the case.
You have currently the cent of BTC, which is roughly 1 cent of USD, but if it goes to be more valuable per unit currency around (currently I don't know any currency being trade at 10 USD) you may need someway to match it with Dollar Cent (which would be 0.001 BTC then)