American Express traveler's checks can be cashed anywhere, but AmEx cashes them without a commission. They're on the little piazza at the end. Normally, the best rates for changing money are not found at the airport, because banks there have a monopoly. Once settled, students exchange information about good places to change money. It is usually disadvantageous to change money at night or on weekends because the number of places open then limits the competition.
Many places offer exchange with no commission, but usually give less advantageous rates.
Students from 1998 said the Bank of Napoli, near the school, was the best place, but usually any bank will do. They don't usually charge a commission and have better rates of exchange. We strongly suggest that you keep any health insurance you have current. If you do not have health insurance, the International Students I.D. Card, which provides you with some discount entrance fees and air fares to many sights, comes with some health insurance. Otherwise you can purchase commercially.