The villages, which are almost unchanged by tourism, are worth a closer look, especially the rather hidden Ginostra with the smallest european port (one boat only!) at all is nice to see. There is a nice beach with fine black lava sand in Stromboli, where one can relax and swim in the sea.
The only real attraction of Stromboli is the volcano itself, which is one of four active volcanos in Italy and the only one which is never asleep. Since the large eruption in April 2003 you have to stay a long way below the craters (guided tours only).
The Euro (EUR), the currency of the European Union, is the official currency of Italy.