This summer my friend and I will be visiting Spain. We are both american citizens, but I am also a Spanish citizen and have a Spanish passport. While we are in Spain, we plan to visit bars and clubs, and purchase drinks requiring ID to be shown. We do not want to take our passports with us for ID, because losing those would be terrible. Are there any alternatives that we can use? We will be there this summer and are both 18, so we don't really know the options available to us.