The peseta was officially retired in 2002 after sufficient time had been given for everyone to exchange the outgoing currency for euros.
In Santiago, a one liter bottle of water costs about 40 cents. Water and groceries in general tend to be cheaper in Spain; I often pay about 25 - 30 euros for a week's worth of groceries. The cost of living here tends to be lower than in the U.S.A., especially compared to in the big American cities. However, there are some exceptions to this rule. For example, gasoline here usually costs about 5 euros per gallon which, at $5.70 is almost twice as much as a fill-up would cost in, say, Chicago.
In Spain, the primary meal is lunch, normally called la comida, which literally translates to "the food" or "the meal." People eat one large meal at about 2:00pm or 3:00pm and may have something small for el desayuno (breakfast) and la cena (dinner). As such, for lunch restaurants often have special offers of multiple course meals, called the menú del día. This week I had a menú at one of my favorite restaurants. The first course consisted of croquetas de jamón, which are small, fried balls of cheese with pieces of Iberian ham inside. For the second course, I had fabada, a stew typical to Galicia and the nearby region of Asturias. It is a bean stew, served warm, that often also includes pork, bacon, and/or chorizo. For dessert, I had cheesecake and a café con leche, coffee with milk. All in all a very delicious meal.