Tapas and Pinchos, a photo by Ginas Pics on Flickr.
Originally tapas were the slices of bread or meat which sherry drinkers in Andalusian taverns used to cover their glasses between sips. This was a practical measure meant to prevent fruit flies from hovering over the sweet sherry. The meat used to cover the sherry was normally ham or chorizo, which are both very salty and activate thirst. Because of this, bartenders and restaurant owners began creating a variety of snacks to serve with sherry, thus increasing their alcohol sales. The tapas eventually became as important as the sherry.