Currency
The Indonesian currency is the Roupia. There is many BCA on the island especially in the main cities and tourist areas. To change monney: use only authorised money changers with proper offices and always ask for a receipt. The largest is called PT Central Kuta and they have several outlets. If you are especially nervous, then use a formal bank. You will get a better rate at an authorised money changer though. Avoid changing money in smaller currency exchange offices located within shops, as they more often than not will try to steal money by utilising very creative and "magician"-like methods. Often the rate advertised on the street is nowhere near the rate that they will give you in the end. Many times the rate is set higher to lure you in so that they can con you out of a banknote or two, and when this is not possible, they will give you a shoddy rate and state that the difference is due to commission. This even applies to the places which clearly state that there is no commission.
